[Spv.Generator] Address dotnet-format issues (#5394)

* dotnet format style --severity info

Some changes were manually reverted.

* Restore a few unused methods and variables

* Silence dotnet format IDE0052 warnings

* Address or silence dotnet format IDE1006 warnings

* Address or silence dotnet format CA1069 warnings

* Address review comments

* Address most dotnet format whitespace warnings

* Run dotnet format after rebase and remove unused usings

- analyzers
- style
- whitespace

* Add comments to disabled warnings

* Simplify properties and array initialization, Use const when possible, Remove trailing commas

* Address IDE0251 warnings

* Revert "Simplify properties and array initialization, Use const when possible, Remove trailing commas"

This reverts commit 9462e4136c0a2100dc28b20cf9542e06790aa67e.

* dotnet format whitespace after rebase

* Rename Operand.cs to IOperand.cs

* Update src/Spv.Generator/Module.cs

Co-authored-by: Ac_K <Acoustik666@gmail.com>

* Remove NotNullWhen attribute and use conditional access to avoid NRE

* Fix duplicated enum values

* Remove unread member

---------

Co-authored-by: Ac_K <Acoustik666@gmail.com>

src/Spv.Generator/LiteralString.cs

@@ -4,7 +4,7 @@ using System.Text;
 
 namespace Spv.Generator
 {
-    public class LiteralString : Operand, IEquatable<LiteralString>
+    public class LiteralString : IOperand, IEquatable<LiteralString>
     {
         public OperandType Type => OperandType.String;
 
@@ -44,7 +44,7 @@ namespace Spv.Generator
             return DeterministicHashCode.Combine(Type, DeterministicHashCode.GetHashCode(_value));
         }
 
-        public bool Equals(Operand obj)
+        public bool Equals(IOperand obj)
         {
             return obj is LiteralString literalString && Equals(literalString);
         }