Editor.config: insert_final_newline is ignored by Fantomas

[auduchinok]

Original issue: RIDER-72601.

What steps will reproduce the issue?

create a fsharp file in rider without a final newline;
create an .editorconfig file with insert_final_newline=false (either as a global setting or specific for *.{fs, fsi, fsx});
format the file

What is the expected result?
Rider does not insert a final newline.

What happens instead?
Rider inserts a final newline.

[nojaf]

Hi, I'm ok with supporting this.

Perhaps it is as simple as tweaking:

fantomas/src/Fantomas/CodePrinter.fs

Lines 65 to 69 in 9e35634

	let rec genParsedInput astContext ast =
	match ast with
	| ImplFile im -> genImpFile astContext im
	| SigFile si -> genSigFile astContext si
	+> ifElseCtx lastWriteEventIsNewline sepNone sepNln

[nojaf]

Oh, and the default of this setting should be true to be non-breaking.

[nojaf]

Available in 4.6