fix: invalid ESM module path on Windows

[ChenPi11]

Fixes #7089

On Windows, ESM loader only accept a valid file:// URLs when it's a absolute path.
So add file:// prefix and replace \ to '/' to make it a valid URL.

[codecov]

Codecov Report

Attention: Patch coverage is 25.00000% with 6 lines in your changes missing coverage. Please review.

Please upload report for BASE (main@f4f0265). Learn more about missing BASE report.
Report is 9 commits behind head on main.

Files with missing lines	Patch %	Lines
src/node/main.ts	25.00%	2 Missing and 1 partial ⚠️
src/node/routes/vscode.ts	25.00%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #7162   +/-   ##
=======================================
  Coverage        ?   72.39%           
=======================================
  Files           ?       31           
  Lines           ?     1913           
  Branches        ?      414           
=======================================
  Hits            ?     1385           
  Misses          ?      446           
  Partials        ?       82           

Files with missing lines	Coverage Δ
src/node/main.ts	48.18% <25.00%> (ø)
src/node/routes/vscode.ts	24.75% <25.00%> (ø)

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[code-asher]

Interesting! We probably want to do the same in src/node/routes/vscode.ts I imagine? (line 61)

[ChenPi11]

Right. This exception may thrown by vscode.js on Windows.

[code-asher]

Sorry for the delay. Thank you for doing this! The next release of code-server should be out soon, and will include this fix.