Head Ref Tablet: Deleting Notes

**Is your feature request related to a problem? Please describe.**
There seems to be no way to delete notes from a match on the HR screen. Blanking out the "Detail" and tags fields still leaves the note on the match.

**Describe the solution you'd like**
If the note is completely blank, delete the note. For example, if a match has [1 note], and it is later edited to clear all contents, it should be removed such that the match has 0 notes.

**Describe alternatives you've considered**
A delete button on each note to delete it without needing to clear the contents.

**Additional context**
N/A

Start at the Head Ref Tablet match note editing flow described in the issue and reproduce clearing the Detail and tags fields. Check how notes are saved when all contents are blank, then verify that a cleared note leaves the match with 0 notes. The issue does not name files or tests, so locating the relevant entry point will require repository exploration.

Written by the indexing model from the issue text.