[browser] Make boot json file name configurable

[jeromelaban]

This change makes the blazor.boot.json file configurable from msbuild, using WasmBootConfigFileName.

[dotnet-policy-service]

Tagging subscribers to 'arch-wasm': @lewing
See info in area-owners.md if you want to be subscribed.

[maraf]

/backport to release/9.0

[github-actions]

Started backporting to release/9.0: https://github.com/dotnet/runtime/actions/runs/11235453611

[github-actions]

@maraf backporting to release/9.0 failed, the patch most likely resulted in conflicts:

$ git am --3way --empty=keep --ignore-whitespace --keep-non-patch changes.patch

Applying: feat: Make boot json file configurable
Applying: chore: Adjust public properties names, fix missing publish names
Applying: Update src/mono/nuget/Microsoft.NET.Sdk.WebAssembly.Pack/build/Microsoft.NET.Sdk.WebAssembly.Browser.targets
Applying: Add test with custom config name
Using index info to reconstruct a base tree...
M	src/mono/wasm/Wasm.Build.Tests/AssertWasmSdkBundleOptions.cs
M	src/mono/wasm/Wasm.Build.Tests/Blazor/BlazorBuildOptions.cs
M	src/mono/wasm/Wasm.Build.Tests/Blazor/BlazorWasmProjectProvider.cs
M	src/mono/wasm/testassets/WasmBasicTestApp/App/wwwroot/main.js
Falling back to patching base and 3-way merge...
Auto-merging src/mono/wasm/testassets/WasmBasicTestApp/App/wwwroot/main.js
CONFLICT (content): Merge conflict in src/mono/wasm/testassets/WasmBasicTestApp/App/wwwroot/main.js
Auto-merging src/mono/wasm/Wasm.Build.Tests/Blazor/BlazorWasmProjectProvider.cs
Auto-merging src/mono/wasm/Wasm.Build.Tests/Blazor/BlazorBuildOptions.cs
Auto-merging src/mono/wasm/Wasm.Build.Tests/AssertWasmSdkBundleOptions.cs
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
hint: When you have resolved this problem, run "git am --continue".
hint: If you prefer to skip this patch, run "git am --skip" instead.
hint: To restore the original branch and stop patching, run "git am --abort".
hint: Disable this message with "git config advice.mergeConflict false"
Patch failed at 0004 Add test with custom config name
Error: The process '/usr/bin/git' failed with exit code 128

Please backport manually!

[github-actions]

@maraf an error occurred while backporting to release/9.0, please check the run log for details!

Error: git am failed, most likely due to a merge conflict.