fix(redis-enterprise): remove non-existent database action methods

[joshrotenberg]

Summary

Removes three database action methods from crate that call non-existent API endpoints.

Problem

The library contained three methods that always fail with 404:

• BdbHandler::start() - calls /v1/bdbs/{uid}/actions/start
• BdbHandler::stop() - calls /v1/bdbs/{uid}/actions/stop
• BdbHandler::restart() - calls /v1/bdbs/{uid}/actions/restart

Verification

Docker Cluster Testing:

# All return 404 Not Found
curl -k -u "admin@redis.local:Redis123!" -X POST https://localhost:9443/v1/bdbs/1/actions/restart
curl -k -u "admin@redis.local:Redis123!" -X POST https://localhost:9443/v1/bdbs/1/actions/start
curl -k -u "admin@redis.local:Redis123!" -X POST https://localhost:9443/v1/bdbs/1/actions/stop

Documentation Search:
Comprehensive search of redis.io REST API documentation confirms these endpoints do not exist. The complete list of documented database action endpoints is:

• stop_traffic / resume_traffic (NOT the same as stop/start)
• export / import / recover
• optimize_shards_placement / rebalance
• backup_reset_status / import_reset_status / export_reset_status

Search results: https://redis.io/docs/latest/operate/rs/references/rest-api/requests/bdbs/actions/

Changes

Removed Methods:

• crates/redis-enterprise/src/bdb.rs - Removed start(), stop(), restart() methods

Removed Tests:

• crates/redis-enterprise/tests/database_tests.rs - Removed test_database_start, test_database_stop
• crates/redis-enterprise/src/lib_tests.rs - Removed test_database_action_start, test_database_action_stop

Documentation Updates:

• docs/src/enterprise/examples.md - Changed "Rolling Restart" example to use stop_traffic/resume_traffic
• docs/src/enterprise/api-access.md - Updated action list to show actual endpoints

Testing

cargo test --package redis-enterprise  # ✅ All 335 tests pass
cargo clippy --all-targets --all-features -- -D warnings  # ✅ No warnings
cargo fmt --all -- --check  # ✅ Clean

Related Issues

Closes #421 - Database restart command cannot be implemented as the API doesn't support it

Notes

While rladmin restart db exists as a CLI command, it uses internal mechanisms not exposed via the REST API. Users needing to pause traffic should use stop_traffic + resume_traffic instead, though this doesn't achieve the same effect as restarting the database process.