#243: highlight active table row

[magdziarek]

Adding a highlight to table row visible when adding a new survey result or editing an existing one. There are no changes to the behaviour of the column in this PR.

When you hover over a row and start entering an observation, this row will have a yellow highlight like so:

[mathieuLU]

hej Aleksandra ! it looks great to me. I would ask for one detail to fix :) is it possible to avoid the highlighting on the 2 final lines ? (line with buttons and line with total)

[mathieuLU]

i have edited it accordingly ;-) https://github.com/biodiversitydata-se/biocollect/commit/dd74c867be1b08f6d4bb47a9509cbcc3fc2964f5