feat(auth): watch file user provider #14455

Job	Run time
Build GreptimeDB binaries (ubuntu-20.04)	4m 22s
Clippy	2m 1s
Check (windows-latest)	4m 56s
Check (ubuntu-20.04)	1m 25s
Rustfmt	25s
Toml Check	35s
Spell Check with Typos	17s
coverage	11m 39s
Sqlness Test (ubuntu-20.04)	1m 46s
Compatibility Test	26s
Sqlness Test with Kafka Wal (ubuntu-20.04)	2m 31s
Fuzz Test (fuzz_create_table)	4m 42s
Fuzz Test (fuzz_alter_table)	4m 31s
	39m 36s

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