Add frontend test suites/cases for src/components/HomeComponents/Tasks

some frontend components currently have less than 100% or fairly low test coverage, as visible in the coverage report (see screenshot below). this issue tracks the work required to identify and improve coverage for those components.

**notes**

- focus should be on meaningful tests rather than coverage-only tests
- avoid snapshot-only tests unless justified
- no functional changes are expected as part of this issue
- if interested, feel free to mention the file you are working on as a comment, and submit a PR
- please create a separate PR for each file

**tracker for this folder**

- [x] AddTaskDialog
- [ ] TaskDialog
- [ ] Tasks
- [x] Hooks