Use workspace.findFiles instead of glob

[JoeRobich]

isBlazorWebAssemblyProject used glob to search for launchSettings.json files. It was being invoked 3 different times for each project within the workspace by requestWorkspaceInformation.

Based on this advice:

	 * The workspace offers support for [listening](#workspace.createFileSystemWatcher) to fs
	 * events and for [finding](#workspace.findFiles) files. Both perform well and run _outside_
	 * the editor-process so that they should be always used instead of nodejs-equivalents.

Updated isBlazorWebAssemblyProject to use vscode.workspace.findFiles and also use the excluded paths defined in files.exclude

Potential fix for #3673

[codecov]

Codecov Report

Merging #3681 into master will increase coverage by 0.11%.
The diff coverage is 92.3%.

@@            Coverage Diff             @@
##           master    #3681      +/-   ##
==========================================
+ Coverage    89.8%   89.91%   +0.11%     
==========================================
  Files          59       59              
  Lines        1589     1597       +8     
  Branches       89       89              
==========================================
+ Hits         1427     1436       +9     
+ Misses        151      150       -1     
  Partials       11       11

Flag	Coverage Δ
#integration	100% <ø> (?)
#unit	89.91% <92.3%> (+0.11%)	⬆️

Impacted Files	Coverage Δ
src/omnisharp/options.ts	94.73% <92.3%> (+2.08%)	⬆️

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[NTaylorMullen]

Out of curiosity does VSCode pre-fill node_modules in this list?

[JoeRobich]

unfortunately it wasn't set for the dotnet new razor project I created to test with.

[NTaylorMullen]

It might make sense for us to auto-include node_modules and whatever Unity's package folder is if it doesn't already exist.

[JoeRobich]

Maybe this should also include search.exclude.. hmm..

[JoeRobich]

Good news is that Unity seems to create a .vscode/settings.json which has an extensive files.exclude defined

[JoeRobich]

Updated to include search.exclude paths which by default include node_modules. Unity's settings.json includes the Library/PackageCache in its files.exclude so I think we are covered from these scenarios.