improve CI with digest for docker, build and test jobs

[maxknv]

Changelog category (leave one):

• Not for changelog (changelog entry is not required)

Changelog entry (a user-readable short description of the changes that goes to CHANGELOG.md):

CI refactoring that implements digest approach to serve several goals:

1. digest docker images and use digest as a tag to ease the search of required images
2. digest build and tests to support job skipping in case it was successfully done before
3. small improvement for style check to do it before docker build job if possible (image not changed)

resolves #56015

Documentation entry for user-facing changes

• Documentation is written (mandatory for new features)

Information about CI checks: https://clickhouse.com/docs/en/development/continuous-integration/

[robot-clickhouse-ci-2]

This is an automated comment for commit 42d5a4e with description of existing statuses. It's updated for the latest CI running

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Successful checks

Check name	Description	Status
Docs check	There's no description for the check yet, please add it to tests/ci/ci_config.py:CHECK_DESCRIPTIONS	✅ success
Fast test	Normally this is the first check that is ran for a PR. It builds ClickHouse and runs most of stateless functional tests, omitting some. If it fails, further checks are not started until it is fixed. Look at the report to see which tests fail, then reproduce the failure locally as described here	✅ success
Mergeable Check	Checks if all other necessary checks are successful	✅ success
Push to Dockerhub	The check for building and pushing the CI related docker images to docker hub	✅ success
Style Check	Runs a set of checks to keep the code style clean. If some of tests failed, see the related log from the report	✅ success

Check name	Description	Status
CI running	A meta-check that indicates the running CI. Normally, it's in success or pending state. The failed status indicates some problems with the PR	⏳ pending
Performance Comparison	Measure changes in query performance. The performance test report is described in detail here. In square brackets are the optional part/total tests	❌ failure