Improve language code around awaiting and owner action to be more theme based

The following discussion from !88343 (merged) should be addressed:

• @aturinske started a discussion: (+2 comments)

  lament (non-blocking): IMO, part of the reason a string is assigned to a variable is so that if we need to change it, we only need to change it in one place and not have to follow it throughout the codebase changing it multiple places, but it seems this variable name was previously too specific that we had to do that anyways (same with isMemberPendingOwnerApproval above). Perhaps now that is is more generically called action instead of approval, this variable can be left alone no matter what the string is.