feat: detect that a table without a key has join to sharded table

[levkk]

No description provided.

[codecov]

Codecov Report

❌ Patch coverage is 94.80813% with 92 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
pgdog/src/frontend/router/parser/copy.rs	91.98%	27 Missing ⚠️
pgdog/src/backend/schema/test_helpers.rs	87.00%	26 Missing ⚠️
pgdog/src/net/messages/mod.rs	17.64%	14 Missing ⚠️
pgdog/src/backend/schema/join.rs	98.11%	5 Missing ⚠️
pgdog/src/backend/schema/mod.rs	90.00%	5 Missing ⚠️
pgdog/src/frontend/router/parser/statement.rs	98.43%	5 Missing ⚠️
pgdog/src/backend/schema/fk_lookup.rs	98.39%	4 Missing ⚠️
pgdog/src/frontend/router/sharding/value.rs	80.95%	4 Missing ⚠️
pgdog-stats/src/schema.rs	0.00%	1 Missing ⚠️
pgdog/src/backend/pool/shard/mod.rs	90.00%	1 Missing ⚠️

📢 Thoughts on this report? Let us know!