Replace jQuery UI resizable for note editor's images resizing with pure JavaScript solution

[d1vanov]

jQuery is old and it's probably better to migrate away from it if at all possible. Currently there are two strong dependencies on jQuery: resizable table columns (#110) and resizable images within the note editor. The latter is the topic of this issue.
Here's some quickly googled pure JavaScript solution to resizable images problem: https://stackoverflow.com/a/40699175/1217285. Probably there are better ones out there too, need to do some research.