Fix bug in LSF driver resource manipulation

[berland]

If both select and rusage was part of the existing resource string, and some hosts were attempted excluded, the previous code would inject the exclusion string at the wrong spot, failing to locate the correct end of the select statement.

Added tests that triggers the original bug.

Issue Resolves #8255

Approach Use regexp parsing

• [x] PR title captures the intent of the changes, and is fitting for release notes.
• [x] Added appropriate release note label
• [x] Commit history is consistent and clean, in line with the contribution guidelines.
• [x] Make sure tests pass locally (after every commit!)

When applicable

• [ ] When there are user facing changes: Updated documentation
• [ ] New behavior or changes to existing untested code: Ensured that unit tests are added (See Ground Rules).
• [ ] Large PR: Prepare changes in small commits for more convenient review
• [ ] Bug fix: Add regression test for the bug
• [ ] Bug fix: Create Backport PR to latest release

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 86.85%. Comparing base (2ce2080) to head (20cc3ed). Report is 1 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #8256 +/- ## ========================================== - Coverage 86.86% 86.85% -0.01% ========================================== Files 378 378 Lines 23946 23945 -1 Branches 631 636 +5 ========================================== - Hits 20800 20798 -2 - Misses 3067 3074 +7 + Partials 79 73 -6 ```

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