Move file_handle_cache and vm_memory_monitor back to rabbit

[Why]
They were moved from `rabbit` to `rabbit_common` several years ago to
solve an dependency issue because `amqp_client` depended on the file
handle cache. This is not the case anymore.

[How]
The modules are moved back to `rabbit`.

`rabbit_common` doesn't need to depend on `os_mon` anymore. `rabbit`
already depends on it, so no changes needed here.

Author: dumbbell

deps/rabbit_common/src/file_handle_cache.erl renamed to deps/rabbit/src/file_handle_cache.erl

@@ -25,7 +25,7 @@ define HEX_TARBALL_EXTRA_METADATA
 }
 endef
 
-LOCAL_DEPS = compiler crypto public_key sasl ssl syntax_tools tools xmerl os_mon runtime_tools
+LOCAL_DEPS = compiler crypto public_key sasl ssl syntax_tools tools xmerl runtime_tools
 DEPS = thoas ranch recon credentials_obfuscation
 
 # Variables and recipes in development.*.mk are meant to be used from