chore: make yuzu REUSE compliant

[REUSE] is a specification that aims at making file copyright
information consistent, so that it can be both human and machine
readable. It basically requires that all files have a header containing
copyright and licensing information. When this isn't possible, like
when dealing with binary assets, generated files or embedded third-party
dependencies, it is permitted to insert copyright information in the
`.reuse/dep5` file.

Oh, and it also requires that all the licenses used in the project are
present in the `LICENSES` folder, that's why the diff is so huge.
This can be done automatically with `reuse download --all`.

The `reuse` tool also contains a handy subcommand that analyzes the
project and tells whether or not the project is (still) compliant,
`reuse lint`.

Following REUSE has a few advantages over the current approach:

- Copyright information is easy to access for users / downstream
- Files like `dist/license.md` do not need to exist anymore, as
  `.reuse/dep5` is used instead
- `reuse lint` makes it easy to ensure that copyright information of
  files like binary assets / images is always accurate and up to date

To add copyright information of files that didn't have it I looked up
who committed what and when, for each file. As yuzu contributors do not
have to sign a CLA or similar I couldn't assume that copyright ownership
was of the "yuzu Emulator Project", so I used the name and/or email of
the commit author instead.

[REUSE]: https://reuse.software

Follow-up to 01cf05bc75

.ci/templates/build-mock.yml

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2019 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 steps:
   - script: mkdir artifacts || echo 'X' > artifacts/T1.txt
   - publish: artifacts

.ci/templates/build-msvc.yml

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2019 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 parameters:
   artifactSource: 'true'
   cache: 'false'

.ci/templates/build-single.yml

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2019 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 parameters:
   artifactSource: 'true'
   cache: 'false'

.ci/templates/build-standard.yml

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2019 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 parameters:
   version: ''
 

.ci/templates/build-testing.yml

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2019 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 parameters:
   version: ''
 

.ci/templates/format-check.yml

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2019 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 parameters:
   artifactSource: 'true'
 

.ci/templates/merge-private.yml

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2019 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 jobs:
 - job: merge
   displayName: 'pull requests'

.ci/templates/merge.yml

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2019 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 jobs:
 - job: merge
   displayName: 'pull requests'

.ci/templates/mergebot-private.yml

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2019 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 parameters:
   matchLabel: 'dummy-merge'
   matchLabelPublic: 'dummy-merge'

.ci/templates/mergebot.yml

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2019 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 parameters:
   matchLabel: 'dummy-merge'
 

.ci/templates/release-download.yml

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2019 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 steps:
   - task: DownloadPipelineArtifact@2
     displayName: 'Download Windows Release'

.ci/templates/release-github.yml

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2019 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 steps:
   - template: ./release-download.yml
   - task: GitHubRelease@0

.ci/templates/release-private-tag.yml

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2019 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 steps:
   - script: chmod a+x $(System.DefaultWorkingDirectory)/.ci/scripts/merge/yuzubot-git-config.sh && $(System.DefaultWorkingDirectory)/.ci/scripts/merge/yuzubot-git-config.sh
     displayName: 'Apply Git Configuration'

.ci/templates/release-universal.yml

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2019 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 steps:
   - template: ./release-download.yml
   - task: UniversalPackages@0

.ci/templates/retrieve-artifact-source.yml

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2019 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 steps:
 - checkout: none
 - task: DownloadPipelineArtifact@2

.ci/templates/retrieve-master-source.yml

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2019 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 parameters:
   needSubmodules: 'true'
 

.ci/templates/sync-source.yml

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2019 yuzu Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 steps:
 - ${{ if eq(parameters.artifactSource, 'true') }}:
   - template: ./retrieve-artifact-source.yml