gatt_client: delete bonding information if proactive authentication not enabled on re-encryption error

gatt_client: fix unused warning

gatt_client: cache security level

gatt_client: add gatt_client_set_required_security_level

gatt_client: report error if re-encryption fails

gatt_client: track re-encryption status and result

gatt_client: abort request if re-encryption fails

gatt client: register for sm events for proactive authentication

gatt_client: drop notifications/indications until IRK and re-encryption are complete as Responder

gatt_client: drop notifications/indications as Central until re-encrypted

gatt_client: use error_code variable

gatt_client: inline gatt_client_mtu

gatt_client: streamline function, parameters and variable names

remove 'peripheral' term and use gatt_client instead

MISRAC2012-Rule-10.4_a: append 'u' to constant literals when used in unsigned expressions or comparisons

gatt_client: improve input validation

gatt_client: process included service response only if pair_size expected

gatt_client: avoid read out of bounds

GATT Client: allow to register for any notification/indication and/or any connection

gatt_client: set uuid16 to zero when deserializing uuid128 services, characteristics, and descriptors

ignore memcpy return value (always returns first parameter)

MISRAC2012-Rule-14.4_b: compare iterator pointer against NULL in for loops

MISRAC2012-Rule-12.1: add suggested parentheses

MISRAC2012-Rule-12.1: add suggested parentheses

MISRAC2012-Rule-12.1: add suggested parentheses

MISRAC2012-Rule-12.1: add suggested parentheses