[Feature] Delete recordings manually via WebUI

**Describe what you are trying to accomplish and why in non technical terms**

I've been tweaking the FFmpeg settings for my 24/7 frigate recording. During the process days of waste data was produced, therefore I'd like to delete the recorded video. I've directly deleted them from the disk, but it seems that those entries are still shown on the "recordings" webpage, causing confusion (attempting to playback will only result in errors or loading forever).

Therefore, I hope that I can delete recording manually via webui, and can manually sync the recording files with the database.

**Describe the solution you'd like**

In `/recording/{camera_name}` endpoint, "Delete" buttons should be added to the entries on the right sidebar, in granularity of both day and hour.

In the same page, a "Sync with Disk" (maybe other label) button should be added, which calls the (currently unused) `sync_recordings` function in `record.py`.

**Describe alternatives you've considered**
(N/A)

**Additional context**
(N/A)

Start at the `/recording/{camera_name}` endpoint and inspect the right-sidebar entries and their existing day/hour structure. Then read the currently unused `sync_recordings` function in `record.py`; done means the WebUI exposes day- and hour-level deletion plus an action that synchronizes recordings with disk.

Written by the indexing model from the issue text.