Glob pattern matching improvements for netcore/CPS (~1s during solution load of 400 projects)

[arkalyanms]

Child of #6034.

Globs were not a hot path before with netframework, but with CPS using globs, the pattern matching can be optimized, say for example by extension first before groveling through disk.

Below is the default set of blobs from CPS/netcore that comes with every project:

glob	excludedPatterns
**/*.cs	**/*.vssscc, obj\/**, **/*.sln, **/*.*proj, **/*.user, **/.*/**, bin\/**, bin\Debug\/**, obj\Debug\/**
**/*.resx	**/*.vssscc, obj\/**, **/*.sln, **/*.*proj, **/*.user, **/.*/**, bin\/**, bin\Debug\/**, obj\Debug\/**
**/*	**/*.vssscc, obj\/**, **/*.sln, **/*.*proj, **/*.user, **/.*/**, **/*.resx, bin\/**, bin\Debug\/**, **/*.cs, obj\Debug\/**

[ladipro]

Observation: We are evaluating globs even if the corresponding item type is not used. The None items declared in the SDK are a good example.

[drewnoakes]

@ladipro None items are used by the Project System. Removing a text file from None causes it to disappear in Solution Explorer, for example.

[ladipro]

@drewnoakes thank you, that makes sense. Although I still wonder if we can avoid doing this work when building on the command line with dotnet build.