[browser] runtimeConfig via boot config

[pavelsavara]

• extend BootJsonData with runtimeConfig which matches just the runtimeOptions.configProperties part of *.runtimeconfig.json
• load RuntimeConfigJsonPath in GenerateWasmBootJson and in WasmAppBuilder
• drop RuntimeConfigParserTask from browser and move it to WASI msbuild
• convert from json to char** in startup.ts
• library mode initialize_runtime() out of scope

export const config = /*json-start*/{
  "mainAssemblyName": "Wasm.Browser.Sample.dll",
  "debugLevel": -1,
  "globalizationMode": "sharded",
  ...
  "runtimeConfig": {
    "runtimeOptions": {
      "configProperties": {
        "System.Net.Http.WasmEnableStreamingResponse": true,
        "Microsoft.Extensions.DependencyInjection.VerifyOpenGenericServiceTrimmability": true,
        ...
      }
    }
  }
}/*json-end*/;

Fixes #97449
Fixes #112442

[dotnet-policy-service]

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