Allow the running of unsaved files

[swernli]

The additional check for the ".qs" extension in the program config prevented using single file, unsaved buffers with language mode set to Q# in run and debug. Removing this fixes the issue.

[sezna]

I do wonder why this was added in the first place. Surely it was to fix something. But as @minestarks can't speak to it, and the tests are passing...

The only scenario I can think of would be if you try to run a qsharp.json or ipynb file, where the language service is active and the debugger is available, but it wouldn't be sensible to run it. Did you test the behavior in those scenarios?

[sezna]

Approving pending tests I mentioned in above comment

[github-actions]

Benchmark for 5813d24

Click to view benchmark

Test	Base	PR	%
Array append evaluation	331.7±4.97µs	333.0±3.26µs	+0.39%
Array literal evaluation	168.6±1.37µs	186.2±2.15µs	+10.44%
Array update evaluation	412.6±11.87µs	409.9±1.00µs	-0.65%
Core + Standard library compilation	22.8±1.13ms	22.6±1.30ms	-0.88%
Deutsch-Jozsa evaluation	4.8±0.05ms	4.8±0.05ms	0.00%
Large file parity evaluation	34.3±0.19ms	34.5±0.33ms	+0.58%
Large input file compilation	14.0±1.75ms	14.7±1.40ms	+5.00%
Large input file compilation (interpreter)	52.6±3.32ms	53.0±2.52ms	+0.76%
Large nested iteration	31.9±0.20ms	32.1±0.16ms	+0.63%
Perform Runtime Capabilities Analysis (RCA) on Deutsch-Jozsa sample	1578.1±73.19µs	1578.6±87.17µs	+0.03%
Perform Runtime Capabilities Analysis (RCA) on large file sample	8.1±0.44ms	8.1±0.38ms	0.00%
Perform Runtime Capabilities Analysis (RCA) on teleport sample	1450.3±94.08µs	1446.2±68.87µs	-0.28%
Perform Runtime Capabilities Analysis (RCA) on the core and std libraries	28.9±0.64ms	28.9±0.72ms	0.00%
Teleport evaluation	91.8±4.50µs	90.5±3.88µs	-1.42%