DAOS-19087 pool: Recov conts in all reints/extends

[liw]

To avoid leaking container children during reintegration, perform
container recovery in all reintegration modes. Not addressed by this
simple change is the extra delay for a POOL_REINT request.

Fix the backoff-less retrying of -DER_AGAINs from container recovery. It
has been seen to generate 11 million log messages within 2 minutes.

Fix an ilog_modify log message that can't be controled by DD_MASK,
making it unnecessarily harder to turn on debug messages.

Fix segfault

#0  crt_hg_bulk_transfer at src/cart/crt_hg.c:2253
#1  crt_bulk_transfer at src/cart/crt_bulk.c:306
#2  ds_pool_recov_cont_handler at src/pool/srv_target.c:3203
#3  crt_handle_rpc at src/cart/crt_rpc.c:1756

that happens when reintegrating a target on the PS leader, likely caused
by NULL crt_rpc_priv.crp_hg_hdl. The approach is to use the existing
bulk mechanism offered by CaRT for CoRPCs. (The CaRT bug with local bulk
transfers is not addressed by this fix.)

Restore the pre-#18651 behavior that aborts a pool reintegrate operation upon unknown target.

Test-tag: pr rebuild dmg_negative_test

Steps for the author:

• Commit message follows the guidelines.
• Appropriate Features or Test-tag pragmas were used.
• Appropriate Functional Test Stages were run.
• At least two positive code reviews including at least one code owner from each category referenced in the PR.
• Testing is complete. If necessary, forced-landing label added and a reason added in a comment.

After all prior steps are complete:

• Gatekeeper requested (daos-gatekeeper added as a reviewer).

[github-actions]

Ticket title is 'Rebuild and container IV activities may result in orphan container children'
Status is 'In Progress'
Job should run at elevated priority (1)
https://daosio.atlassian.net/browse/DAOS-19087

[liw]

We'll also need to add a backport of #19106 here.