[Generators] Captured msbuild properties do not escape editorconfig reserved characters

[jeromelaban]

Version Used: VS 16.8 Pre 3

Steps to Reproduce:

1. Capture an msbuild property

<CompilerVisibleProperty Include="MyProperty" />

2. Set the property:

<MyProperty>Value1;Value2</MyProperty>

3. Read the property

context.AnalyzerConfigOptions.GlobalOptions.TryGetValue($"build_property.MyProperty", out var value);

Expected Behavior:
The value is Value1;Value2

Actual Behavior:
The value is Value1

[sharwell]

Duplicate of #44596

[sharwell]

📝 I don't believe there is any escape sequence for the two characters # and ;.