[browser] download sequence optimization

[pavelsavara]

• when startupMemoryCache false or memory cache is empty, we could fetch DLLs earlier
• fixed HTML prefetch in samples
• disabled throttling on perf bench
• moved checking for memory snapshot to configureRuntimeStartup
• fixed loading .wasm always
• calling library initializers and onConfigLoaded for manual config too

Related #89631 #89857 #89687 dotnet/aspnetcore#49909

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Issue Details

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Author:	pavelsavara
Assignees:	pavelsavara
Labels:	arch-wasm, area-System.Runtime.InteropServices.JavaScript, os-browser
Milestone:	8.0.0

[pavelsavara]

@radekdoulik could you please measure this on your bench before we merge it ? To see if this helps with AOT and cold start.
thank you!

[pavelsavara]

@maraf , please consider also adding cacheBootResources =true for non-blazor.
It could improve "Reach managed" + "no-cache" combination.

[pavelsavara]

Also with no-cache & perfetch, is FF fetching it twice ?

[lewing]

Makes sense to me assuming it improves things.

[kg]

Looks fine, but there are some parts I don't completely understand the significance of

[maraf]

Looks good to me 👍

[pavelsavara]

/backport to release/8.0

[github-actions]

Started backporting to release/8.0: https://github.com/dotnet/runtime/actions/runs/5998747142

[github-actions]

@pavelsavara backporting to release/8.0 failed, the patch most likely resulted in conflicts:

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

Applying: attempt
Applying: oh whitespace!
Applying: - resolve memorySnapshotSkippedOrDone earlier
Applying: fix minimal sample
Applying: - moved checking for snapshot to `configureRuntimeStartup`
error: sha1 information is lacking or useless (src/mono/wasm/runtime/startup.ts).
error: could not build fake ancestor
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0005 - moved checking for snapshot to `configureRuntimeStartup`
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".
Error: The process '/usr/bin/git' failed with exit code 128

Please backport manually!

[github-actions]

@pavelsavara an error occurred while backporting to release/8.0, please check the run log for details!

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