feat: add CSVQ support for rule parsing

[encima]

What kind of change does this PR introduce?

Feature

What is the current behavior?

Currently, inspect reports are quite modular and provide output where column titles can vary

What is the new behavior?

• Refined queries to output in a similar format and reduced/combined work to minimise the number of output files produced (or commands needed)
• Support custom validation rules in supabase/config.toml

[[experimental.inspect.rules]]
query = "SELECT LISTAGG(stmt, ',') AS match FROM `locks.csv` WHERE age > '00:02:00'"
name = "No old locks"
pass = "✔"
fail = "There is at least one lock older than 2 minutes"

Additional context

CSVQ has been added as a library to provide a table printout of some rules that are/are not met by the CSV files produced by report

[coveralls]

Pull Request Test Coverage Report for Build 15578639723

Details

• 41 of 132 (31.06%) changed or added relevant lines in 11 files are covered.
• 6 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.5%) to 54.614%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
internal/inspect/report.go	7	11	63.64%
internal/inspect/db_stats/db_stats.go	13	19	68.42%
cmd/inspect.go	0	81	0.0%

Files with Coverage Reduction	New Missed Lines	%
cmd/inspect.go	1	0.0%
internal/gen/keys/keys.go	5	12.9%

Totals
Change from base Build 15552166588:	-0.5%
Covered Lines:	5877
Relevant Lines:	10761

---

💛 - Coveralls

[sweatybridge]

Suggested change

	table := "|Name|Last Vacuum|Last Auto Vacuum|Row count|Dead row count|Expect autovacuum?\n|-|-|-|-|-|-|\n"
	table := "|Table|Last Vacuum|Last Auto Vacuum|Row count|Dead row count|Expect autovacuum?\n|-|-|-|-|-|-|\n"

For clarity and consistency with unused_indexes.

[sweatybridge]

why are we converting to json then back to number?