Filter by Date Range

**Is your feature request related to a problem? Please describe.**

There is no way to filter by a date range.

**Describe the solution you'd like**

Add a date range selector to the `filter-bar` component to allow for filtering by start and end dates, we could perhaps use the `created_at` field for the filtering.

An additional feature could be to have a few pre-determined date ranges, like:

- this week (past 7 days)
- this month (past 30 days)
- old (older than 30 days)

The user could select from a dropdown and quickly populate the date range selector.

After adding this date range selector, the `filter-bar` component might be too cramped on smaller screens (e.g. split screen on a laptop). So, it might be a good idea to split the `filter-bar` into two rows, if the items in the component become too small.

**Describe alternatives you've considered**

One possible workaround is to create milestones for each time period. However, this needs to be manually created and the milestones have to be assigned individually to the issues / PRs. Furthermore, this cannot be done within WATcher itself.

**Additional context**

This might not be super helpful for CS2103 TP teams, but I think it would be useful for larger repositories, and might be worth looking into!

Start with the `filter-bar` component and inspect how its existing filters use issue or pull-request data. Define completion as filtering by start and end dates, optionally selecting the proposed presets, and keeping the controls usable on smaller screens; verify the behavior with the component's existing checks if available.

Written by the indexing model from the issue text.