* BLERemoteChar: fix descriptor 2902 write for characteristic notifications

When registering a notification on a characteristic, the 2902 descriptor
(CCCD) value is set to 1 (or 2 for indication).
According to the BLUETOOTH CORE SPECIFICATION Version 5.2, Revision Date
2019-12-31, section 4.12.3 "Write Characteristic Descriptors" (page 1588),
the characteristic descriptor write must expect a response.
Currently, the descriptor write is performed without expecting a reponse,
which prevents the notification to be functional with some BLE stacks.
This commit modify the write to expect the response.
Signed-off-by: NJimmy Durand Wesolowski <jimmy.durand.wesolowski@commsolid.com>

* BLERemoteChar: forward GATT client event to characteristic descriptors

This commits prevents a permanent wait when calling BLERemoteDescriptor
readValue function, on the m_semaphoreReadDescrEvt semaphore.

ESP32 BLE stack calls to remote characteristic
- notification,
- value read
- value write
and remote characteristic descriptor
- value read
are asynchronous.

When such a call is performed by this library, a semaphore is taken prior
to the BLE stack read or write operation, and waited on after it.

Releasing the semaphore is done by the characteristic event handling
function (gattClientEventHandler), when the appropriate event is received.

However, the characteristic descriptor events are discarded, and the
value read semaphore is never released.

This commits forwards the GATT client events from the remote
characteristic down to their remote characteristic descriptor, and
implements their event handling.

Adding a semaphore for the remote characteristic descriptor value write
will be done in a separate commit.
Signed-off-by: NJimmy Durand Wesolowski <jimmy.durand.wesolowski@commsolid.com>

* BLERemoteDescriptor: add semaphore to characteristic descriptor write

This adds a semaphore to characteristic descriptor value write, to mimic
the value read function, and to ensure completion of the operation before
we carry on.
Signed-off-by: NJimmy Durand Wesolowski <jimmy.durand.wesolowski@commsolid.com>
Co-authored-by: NJimmy Durand Wesolowski <jimmy.durand.wesolowski@commsolid.com>