Casual record form: add taxon group filter options

[sacrevert]

On some recording forms, e.g. the standard 'add a list' form, there is a filter button next to the species column, and one of the filtering options is to use the account setting taxon group/s:

It would be useful to have this functionality on the 'Enter a casual record" form too

[johnvanbreda]

This needs a few hours as it requires new code.

[sacrevert]

Not a priority for me, just seems like something useful (and harmonises different forms a bit more)