Ruben/test task

[Arzoyan]

Contribution checklist

Brief description

Add new feature.
when employee go to vacation (out of office) in that period you can't assign task that user

Checklist

• [X] - UI test added to added/changed functionality?
• [X] - Screenshot is added to PR if applicable ?
• [X] - Does a local formatting is applied (rush format)
• [X] - Does a local svelte-check is applied (rush svelte-check)
• [X] - Does the code work? Check whether function and logic are correct.
• [X] - Does Changelog.md is updated with changes?
• [X] - Does the translations are up to date?
• [X] - Does it well tested?
• [X] - Tested for Chrome.
• [X] - Go through the changed code looking for typos, TODOs, commented LOCs, debugging pieces of code, etc.

verification/signing-commits)