test: add tests for drop databases #14509

Job	Run time
Spell Check with Typos	18s
Check (windows-latest)	6m 5s
Build GreptimeDB binaries (ubuntu-20.04)	4m 15s
Clippy	2m 18s
Check (ubuntu-20.04)	1m 31s
coverage	11m 11s
Rustfmt	28s
Toml Check	35s
Sqlness Test (ubuntu-20.04)	1m 59s
Sqlness Test with Kafka Wal (ubuntu-20.04)	2m 22s
Fuzz Test (fuzz_create_table)	4m 38s
Compatibility Test	59s
Fuzz Test (fuzz_alter_table)	5m 7s
	41m 46s

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