Refactor: improve and clean up Dockerfiles

[MonkeyCanCode]

What changes were proposed in this pull request?

1. Combine multiple RUN layers into a single RUN layer to reduce image size
2. Combine ENV/ARG instructions for easily readability
3. Load polaris spark job automatically instead of hard-coded value and only copied needed jar instead of whole directory
4. Cleanup and simplify Dockerfiles

Why are the changes needed?

General cleanup and simplify existed dockerfiles

Does this PR introduce any user-facing change?

No

How was this patch tested?

Tested with various test suits we have around those docker files such as docker-compose instructions.

CHANGELOG.md

N/A

[snazy]

This is a nice improvement to image build performance! Thanks for this!
Some comments though, nothing dramatic.

[MonkeyCanCode]

@snazy all comments should be addressed now. Please take another look when you have a chance.