…ra code (Seagate#356)

* rgw_sal_motr, motr_gc: [CORTX-33148] add MotrGC, MotrGC::GCWorker infra code

Behaviour
- With Garbage Collector enabled, MotrGC will have GC indexes & GC worker threads.
- GC worker threads will run for the configured max processing time and then
   will wait for the configured time between two consecutive runs.

Additions/Changes
- Add the Garbage Collector infrastructure to support the start & stop of worker threads.
  - MotrGC class with the interfaces to initialize(), start(), stop() and finalize().
  - GCWorker class with entry() and stop() methods.
- Refactor Initialization of MotrStore
  - add setter methods to configure MotrStore
 - add initialize() method to call initialization of all the other components
   eg. MetadataCache, GC, (in future LC, QuotaHandler), etc.

Signed-off-by: Sumedh Anantrao Kulkarni <sumedh.a.kulkarni@seagate.com>

The GC thread will aquire GC index and process the object entries for
deletion either upto the count governed by "rgw_gc_max_trim_chunk" or
time allowed by "rgw_gc_processor_max_time".

Signed-off-by: Sachin Punadikar <sachin.punadikar@seagate.com>

Seagate#373)

* rgw_sal_motr: [CORTX-33691] Defines abstract synchronization primitives
and implements it for Motr GC across multiple RGW instances.

Signed-off-by: Dattaprasad Govekar <dattaprasad.govekar@seagate.com>

* motr_sync_impl: [CORTX-33691] update lock() & remove_lock() methods

Update and refactor the MotrLock::lock() and MotrKVLockProvider::remove_lock()
methods.

Signed-off-by: Sumedh Anantrao Kulkarni <sumedh.a.kulkarni@seagate.com>

Co-authored-by: Dattaprasad Govekar <dattaprasad.govekar@seagate.com>

…gate#379)

* rgw_sal_motr, motr_gc: [CORTX-32689] Implement MotrGC::enqueue()

* Push {0_ObjTag: motr_gc_obj_info} and {1_ExpiryTime: motr_gc_obj_info}
  entry to the gc queues, i.e. motr dix.
* Call gc->enqueue() method on simple object delete request without
  actually deleting the obj.

Signed-off-by: Sumedh Anantrao Kulkarni <sumedh.a.kulkarni@seagate.com>

* motr_gc: [CORTX-32689] Implement MotrGC::list() function

MotrGC::list() goes through every gc queue and lists the adds the
pending delete requests in resultant vector.
Interface to list objs using admin tool or rest api's is yet
to be developed.

Signed-off-by: Sumedh Anantrao Kulkarni <sumedh.a.kulkarni@seagate.com>

… Motr

- Integrate locking code changes in GC worker thread.

Signed-off-by: Dattaprasad Govekar <dattaprasad.govekar@seagate.com>

… Motr

- Integrate locking code changes in GC worker thread

Signed-off-by: Dattaprasad Govekar <dattaprasad.govekar@seagate.com>