this is a major overhaul by migrating off all
bucket metadata related configs into a single
object '.metadata.bin' this allows us for faster
bootups across 1000's of buckets and as well
as keeps the code simple enough for future
work and additions.
Additionally also fixes#9396, #9394
This PR also tries to simplify the approach taken in
object-locking implementation by preferential treatment
given towards full validation.
This in-turn has fixed couple of bugs related to
how policy should have been honored when ByPassGovernance
is provided.
Simplifies code a bit, but also duplicates code intentionally
for clarity due to complex nature of object locking
implementation.