[browser] Wasm SDK packed as a nuget package

[maraf]

Produce a Microsoft.NET.Sdk.WebAssembly.Pack package containing most of the Wasm SDK bits.

• Contains original PR [browser] Wasm SDK packed as a nuget package #84082 and fix for official build [wasm] Fix publishing Microsoft.NET.Sdk.WebAssembly.Pack #84754
• Original sources https://github.com/dotnet/sdk/tree/main/src/WasmSdk
• This PR tries to make a minimal change
• Tests and integration with in-tree building will come in follow-up PRs
• Update pattern for matching RidAgnosticNupkgToPublishFile to include Microsoft.NET.Sdk.WebAssembly.Pack

Contributes to #81367
Fixes #84742

[ghost]

Tagging subscribers to 'arch-wasm': @lewing
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Issue Details

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Produce a Microsoft.NET.Sdk.WebAssembly.Pack package containing most of the Wasm SDK bits.
Original PR #84082

• Original sources https://github.com/dotnet/sdk/tree/main/src/WasmSdk
• This PR tries to make a minimal change
• Tests and integration with in-tree building will come in follow-up PRs
• Update pattern for matching RidAgnosticNupkgToPublishFile to include Microsoft.NET.Sdk.WebAssembly.Pack

Contributes to #81367

Author:	maraf
Assignees:	maraf
Labels:	arch-wasm, area-Build-mono
Milestone:	8.0.0

[maraf]

The official build https://dev.azure.com/dnceng/internal/_build/results?buildId=2157605&view=results

[maraf]

The official build has completed and I have validated in binlog that the items collection ItemsToPush contains Microsoft.NET.Sdk.WebAssembly.Pack. The task PushToAzureDevOpsArtifacts doesn't run for branch build.

Failures are not related

@lewing This is ready to merge

[maraf]

We should wait for this dotnet/sdk#31559 to land in SDK and update StaticWebAssets binding