fix: Add `fetchVariable` parameter support in ActivateJobs RPC

[ce-dmelnych]

Description

Enhanced the activateJobs method in the GrpcToLogStreamGateway class to support the fetchVariable parameter. This addition allows clients to specify which variables should be fetched when activating jobs. The change also includes a new test to verify that only the specified variables are returned on job activation.

Related issues

closes #675

Definition of Done

Not all items need to be done depending on the issue and the pull request.

Code changes:

• [x] The changes are backwards compatibility with previous versions
• [x] If it fixes a bug then PRs are created to backport the fix

Testing:

• [ ] There are unit/integration tests that verify all acceptance criterias of the issue
• [x] New tests are written to ensure backwards compatibility with further versions
• [ ] The behavior is tested manually

Documentation:

• [ ] Javadoc has been written
• [ ] The documentation is updated

[github-actions[bot]]

Test Results

 50 files  ±0   50 suites  ±0   1m 56s :stopwatch: +11s 135 tests +1  135 :white_check_mark: +1  0 :zzz: ±0  0 :x: ±0  429 runs  +3  429 :white_check_mark: +3  0 :zzz: ±0  0 :x: ±0 

Results for commit 1d989112. ± Comparison against base commit 2d690915.

:recycle: This comment has been updated with latest results.

[ghost]

Build succeeded:

• Test summary

[backport-action]

Backport failed for stable/8.1, because it was unable to cherry-pick the commit(s).

Please cherry-pick the changes locally and resolve any conflicts.

git fetch origin stable/8.1
git worktree add -d .worktree/backport-1058-to-stable/8.1 origin/stable/8.1
cd .worktree/backport-1058-to-stable/8.1
git switch --create backport-1058-to-stable/8.1
git cherry-pick -x b6705cb24201a156c4fe02b082d22d7eb32f9f29 1d9891127e70875d12ce920bfc852f5944c82001

[backport-action]

Backport failed for stable/8.2, because it was unable to cherry-pick the commit(s).

Please cherry-pick the changes locally and resolve any conflicts.

git fetch origin stable/8.2
git worktree add -d .worktree/backport-1058-to-stable/8.2 origin/stable/8.2
cd .worktree/backport-1058-to-stable/8.2
git switch --create backport-1058-to-stable/8.2
git cherry-pick -x b6705cb24201a156c4fe02b082d22d7eb32f9f29 1d9891127e70875d12ce920bfc852f5944c82001

[backport-action]

Backport failed for stable/8.3, because it was unable to cherry-pick the commit(s).

Please cherry-pick the changes locally and resolve any conflicts.

git fetch origin stable/8.3
git worktree add -d .worktree/backport-1058-to-stable/8.3 origin/stable/8.3
cd .worktree/backport-1058-to-stable/8.3
git switch --create backport-1058-to-stable/8.3
git cherry-pick -x b6705cb24201a156c4fe02b082d22d7eb32f9f29 1d9891127e70875d12ce920bfc852f5944c82001

[backport-action]

Successfully created backport PR for stable/8.4:

• 1059

[korthout]

@ce-dmelnych Please follow the instructions above, and resolve any conflicts, to backport these changes to 8.3, 8.2, and 8.1. 🙇

Feel free to request a review from me on these PRs.