Tracking issue - improve FSI debugging

[KevinRansom]

FSharp Interactive debugging was never good, and it has got much worse.

This is a tracking bug to try to collect the activities that may improve it.

• [ ] Debugging can't find source. The generated multi-emit symbol files do not contain source.
• [ ] Performance: Symbol files are always generated even when not debugging
• [ ] Watch variables do not work: #14572
• [ ] Local variables do not work: related to #14572
• [ ] There should be a separate set of configurable options when debugging, such optimization off, tailcall off.
• [ ] Debugging should not require disable "Just my code": #17148,
• [ ] While using the VisualFSharp solution it should be easier to debug a local coreclr build
• [ ] Visual Studio selects the highest version of the sdk installed on the machine when executing scripts in FSI #17307
• [ ] We should disable the --multiemit[+/-] switch in fsi. #17308

[rgbav]

pleeeaaaase someone implement proper script debugging. This is a very important feature to convince others to use F# for scripting and to be more enjoyable for beginners.