Audio recording of tree species name (feature request)

**Is your feature request related to a problem? Please describe.**

The challenge of identifying tree species from the photos is great. The first task is always classing images at a site into 'morphospecies' that appear to be different, even before trying to match a morphospecies to a scientific name. Having additional information would help greatly, to: i) build morphospecies lists for each site, ii) indicate when two similar morphospecies are different, iii) _possibly_ assist in matching to scientific name (where local names have been documented), and iv) provide a different kind of data for machine learning training. It is likely that many planters will know the local names for the (usually) small set of species they are planting. But at the moment this information is not captured.

**Describe the solution you'd like**

* On the screen showing the photo, after it has been taken, a big, round button (mimicking 'Record' in other apps) would be visible. It should contain an image of a tree, to remind the planter to speak the name of the plant.
* While it is pressed _and held_, audio would be recorded, to a maximum of 5 seconds.
* On releasing the button the audio would play back.
* Pressing the button again for the same image would re-record the audio.
* A low-res MP3 would be saved, _with the same UUID_ as the photo.

**Describe alternatives you've considered**

Text input of species information. But this would exclude some planters, and the various spellings of the transliteration of the spoken name would be great.

**Additional context**

Discussed this with @sebastiangaertner, who encouraged me to add this as an issue.