fallback to vsfutil.loadtext when readDocument is null

[uinstinct]

Description

readFile in jetbrains has a fallback but readDocument returned empty string. This PR fixes it by returning null so that it can successfully fallback.

closes CON-4770

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• [] The relevant tests, if any, have been updated or created

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Summary by cubic

Fixes IntelliJ file reading to fall back to vsfutil.loadtext when the editor document is unavailable. Prevents empty content by reading from disk as intended (CON-4770).

• Bug Fixes
  • Return null instead of "" in readDocument to trigger readFile's vsfutil.loadtext fallback.

^{Written for commit 82050fc. Summary will update automatically on new commits.}

[uinstinct]

need to verify on a build

EDIT: seems to work

[cubic-dev-ai]

No issues found across 1 file