Ability to specify media compression per upload

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

It's very frustrating not to be able to pick when media should be sent full resolution or compressed on a case by case basis - eg if you want to save data, or fit a huge video under 100MB, or send the original media, etc.

**Describe the solution you'd like**

On the upload+caption screen, how about we have a context menu which has a setting which you can adjust per upload if you have particular compression requirements?

**Describe alternatives you've considered**

We used to just prompt for each upload, but this got rejected for being too techie. Then we got a global setting, which is very unergonomic to change and only has "original v compressed". Instead, how about we let the user pick if they care on a per upload basis?