Cherry pick ob1 fixes to release branches

[jsquyres]

Need to cherry-pick the commits from the PRs listed below to v2.x, v3.0.x, v3.1.x, and v4.0.x:

• pml/ob1: fixed local handle sent during PUT control message #6556 (e630046): pml/ob1: fixed local handle sent during PUT control message
• Fix the leak of fragments for persistent sends (issue #6565) #6621 (a16cf0e): Fix the leak of fragments for persistent sends

Note that a16cf0e contains use of OPAL_THREAD_SUB_FETCH_SIZE_T and OPAL_THREAD_ADD_FETCH_SIZE_T, neither of which exist before v4.0.x. Porting to the older branches is therefore a bit complex -- I took a whack at it and was not confident enough in what I finally managed to get to compile.

[jsquyres]

FYI: @EmmanuelBRELLE

[bosilca]

I'm working on a fix for the PUT issue. If there is no rush to push this in, let's wait for few days until I'm done.

[jsquyres]

@bosilca Any updates? We're looking at the possibility of 4.0.2 in the "near" future.

[bosilca]

Not enough hours in a day. I'm on the datatype issue right now, so I put this one aside. I might get to it before the end of the week.

[gpaulsen]

@bosilca Any updates? We're looking at the possibility of 4.0.2 in the "near" future.