[TODO] nimsuggest: allow handling random files not yet known

[timotheecour]

/cc @Araq @PMunch @krux02

• fixes no more projectfile.nim as argument nimsuggest#66
• refs Find project file PMunch/nimlsp#8
• fixes nimsuggest#96
  docs say https://nim-lang.github.io/Nim/nimsuggest.html

There is some support so that you can throw random .nim files which are not part of myproject at Nimsuggest too, but usually the query refer to modules/files that are part of myproject.

this wasn't true until this PR
it's a very useful feature that allows you to handle nim files not covered by your initial project.nim

• nimsuggest can handle files not yet known
• add refresh option
• auto-refresh main file when unknown file is provided (given via --autoupdatedMainFile:file to make it very clear it'll be auto-updated)

note

• my previous approach was [superseded] nimsuggest: fix nimsuggest#96 ; nimsuggest can handle files not yet known #9715 ; it was very simple (2 line change) and worked in a number of cases (and was more efficient, since it didn't require full recompilation on unknown files), but led to crashes in other cases so wasn't as robust as this PR

• if there's a better way than updating input file (given by --autoupdatedMainFile:file) I'm happy to take suggestions; otherwise this PR works fine

[Araq]

I liked your previous solution much better and the crashes could have been fixed, I think. The ModuleGraph can have multiple entry points, in theory there is not much to it.