Add easily accessible "refresh parameter description" button

We quite commonly see users complain that they don't see the latest parameter descriptions. For example this morning I received a question, "Why doesn't the RNGFND_TYPE parameter description include 25 for Benewake TFmini Plus?".

I normally tell the users they need to update their parameter descriptions which involves:

- open flight data screen
- press Ctrl-F to expose the potentially scary window of buttons
- press paramgen

Maybe we could add a button either on the bottom of the Help page (where the check for updates is) or in the full parmeter list page.

Start by examining the Help page's update controls and the full parameter list page, then trace the existing Ctrl-F and paramgen workflow from the flight data screen. Done means users can access a refresh-parameter-descriptions button from one of the proposed locations and it performs the same update action.

Written by the indexing model from the issue text.