fix(mysql): add lock_wait_timeout to DSN to stop statement pile-up

[jabbrwcky]

Description of your changes

Under a backlog of pending ALTER USER/GRANT/DDL statements, MySQL/Percona can become unresponsive. go-sql-driver/mysql cancels a context by closing the TCP socket without sending KILL QUERY (intentional; all versions incl. latest v1.10.0). With MySQL's default lock_wait_timeout of 1 year, a statement blocked on a metadata/ACL lock (e.g. behind a backup or long transaction) stays pending server-side even after the 60s reconcile deadline. Every retry adds another; account-management statements serialize on a single global ACL lock, so they pile up until max_connections is exhausted or the server wedges.

This PR appends lock_wait_timeout=30 and dial timeout=10s to the MySQL DSN so blocked statements fail fast server-side and release instead of accumulating. Applies to all MySQL controllers (User, Grant, Database; cluster + namespaced) via the shared client.

Not covered / follow-ups:

• Non-lock hangs (dead network, server wedged mid-execution) still only get socket-closed-without-KILL; app-level KILL QUERY is the only remedy.
• Bounded shared connection pool (per-query sql.Open) — separate concern, see Provider should use connection pooling or single transaction to minimize load on database when reconciling  #195.
• Making lock_wait_timeout configurable via ProviderConfig.

See docs/mysql-driver-context-cancellation.md for the full analysis.

Fixes #422

I have:

• Read and followed Crossplane's contribution process.
• Run make reviewable to ensure this PR is ready for review.

How has this code been tested

• Updated DSN assertions; added TestDSNParsesWithLockWaitTimeout validating the DSN parses via the driver and carries the params.
• go build ./..., go vet, and full MySQL controller test suites pass.
• make and make reviewable pass.

[jabbrwcky]

Superseded by #435 (same branch got wiped by a bad rebase, GitHub wouldn't let this PR reopen after recovery).