distance editing window: TAB key and auto-highlight

in RC, the TAB key is used to “jump” from the left to the right side of a 1D(s) panel,

it also highlights/preselects the value on the right side of the panel,

see also:

https://support.capturingreality.com/hc/en-us/community/posts/115001350592-tab-key-to-move-between-fields

https://support.capturingreality.com/hc/en-us/community/posts/115000776331-Navigating-menus?page=1#community_comment_360001347251