fix dynamic containers rm function after v4 migration

[dmytrotkk]

This pull request updates the logic for discovering and removing Docker containers related to "skaled" and "IMA" services, expanding support for both new and legacy container name prefixes. It also adds comprehensive tests to ensure both naming conventions are handled correctly.

Docker container discovery and removal improvements:

• Updated get_all_skaled_containers and get_all_ima_containers in docker_utils.py to return containers matching both the new (sk_*) and legacy (skale_*) name prefixes, ensuring compatibility with containers created under either convention.
• Renamed related functions and log messages from "schain" to "skaled" for clarity and consistency.

Testing enhancements:

• Added tests in docker_utils_test.py for get_all_skaled_containers and get_all_ima_containers to verify that both new and legacy prefixes are detected, using mocked Docker clients and containers. [1] [2]