Refactored IMAP IDLE push bundle (US76128986) incl. config changes

The following properties are removed from file:
- com.openexchange.push.imapidle.errordelay
- com.openexchange.push.imapidle.debug

The following properties are added to file:
- com.openexchange.push.imapidle.delay
- com.openexchange.push.imapidle.clusterLock

Description for new properties:

# Waiting time in milliseconds before a reconnect is performed
# Default value is 5000

# Specifies what system to use to manage a cluster-lock
# Possible values:
# - db for database-based locking
# - hz for Hazelcast-based locking (default)
# - none for no cluster lock mechanism
# Default value is hz