Fix double-free throughout amqp_definitions

[ewertons]

This is related to issue 84965 (work item 186232).

The bugs identified in open_get_offered_capabilities are correct. open_get_offered_capabilities is implemented in amqp_definitions.c, which is autogenerated from amqp_definitions_c.tt. amqp_definitions_c.tt is also used to autogerate functions for other AMQP composite types. By fixing amqp_definitions_c.tt (function in lines 317 to 494) this double-free bug pattern is being addressed for:

• open_get_outgoing_locales
• open_get_incoming_locales
• open_get_offered_capabilities
• open_get_desired_capabilities
• begin_get_offered_capabilities
• begin_get_desired_capabilities
• attach_get_offered_capabilities
• attach_get_desired_capabilities
• sasl_mechanisms_get_sasl_server_mechanisms
• source_get_outcomes
• source_get_capabilities
• target_get_capabilities