[Blazor] Tracking end-to-end fingerprinting in standalone mode

[maraf]

• Write import map to html files sdk#46233
• Allow to fingerprint Blazor.js sdk#46988
• Put only hard fingerprinted files into import map during publish sdk#47515
• Update templates (wasmbrowser+blazorwasm)
• Clean-up SDK WriteImportMapToHtml=>OverrideHtmlAssetPlaceholders flows through

[maraf]

After offline discussion, we might proceed with enabling the feature in template and not enabling it by default in the SDK. Meaning it would need a manual upgrade in existing apps.

[maraf]

Maybe we can copy fingerprinted & not-fingerprinted dotnet.js & blazor.js into publish output and produce a console warning if non-fingerprinted file is used (credit @akoeplinger)

[akoeplinger]

not sure if it'd be easier than duplicating the files but I thought something like this:

console.warn("Directly importing blazor.js is not recommended. Please use fingerprinting.");

const script = document.createElement('script');
script.type = 'text/javascript';
script.src = './blazor.XYZ.js';
document.head.appendChild(script);