PIP-13-3/3: auto subscribe based on regex pattern topics changing

[zhaijack]

This change is based on work of #1165, which already contains the first 6 commits there.
In this PR, only the last commit is for this sub-task.

will update it once PIP-13-2/3 merged.

Motivation

This is a last sub-task for pip-13, which would auto subscribe new topics, based on regex pattern topics changing subscription.

Modifications

• add TopicsChangedListener to track topics change.
• do auto subscribe/unsubscribe based on topics changes.
• add test cases to verify.

Result

old methods behaviour not changed,
user could use new method to subscribe to topics based on regex pattern, and do auto subscribe

[zhaijack]

close this for too much conflict, will open new one