…sionsSometimes it can be useful to have additional info collected with wait_events,so we add two new views/functions that include more information. The structure ofthose views could be changed in new versions of pg_wait_sampling extension

Also fix some typos/reword some sentences

- Rename some columns in code and in GUC allowed values- Change client_addr type to inet as in pg_stat_activity- event value for dimension GUC now turn both wait_event and  wait_event_type on and off; event_type not supported- README formatting- Hide leader_pid for leader process- Reset profile and history after reloading configuration,  but only if dimensions have changed- Disallow passing empty string as dimensions- pid and queryid are NULL now if are not in dimenstions- empty client_hostname is now NULL like in pg_stat_activity- empty appname is now shown as empty string as in pg_stat_activity

- Remove unneded palloc- Move initialization of possibly-null fields behind mask-checking  (in fill_values_and_nulls function)- Switch api_version and parameter amount in *_internal functions,  this makes safety check look better- Remove pgstat_clear_*** from pg_wait_sampling_get_current,  it could mess with other functions unexpectedly- Use correct bitmask in get_profile/history_internal- Add dimensions_mask to Profile and History to save it through  multiple calls to get_profile/history- Use statically allocated varialbes ts and count in deserialize_array- Take care of padding in deserialize_array- Leave only common_dimensions in probe_waits- Remove unneded +1 in serialize_item- Remove serialized_key in probe_waits, it's not needed- Add pfree to stop leaking serialized_item- Always copy only count to hash table in probe_waits