[WIP]Formatting

[bung87]

waiting for nimpretty compile project without problem.

[bung87]

This won't work. The filestash file is the file as it appears in the editor for the user even if they haven't saved. We're only updating this based on the text changing events received from the editor. This would discard all changes the user have made without saving and mess up the internal cache file.

then we can take filestash as input file , and save formatted file to somewhere then read the content attach to response.

[AmjadHD]

why did this stop ?

[bung87]

this PR has two purposes. one for add code formatting feature, one for reduce the code complexity of nimlsp its self.
for code formatting , the nimpretty is not flexible to such a use case , it will cause compilation error as last commit message.
for reduce the code complexity of nimlsp , the nimlsp use alternative solution, also as nim became 1.6 version , it's not easy as before triggering nimlsp shutdown.