Early leave findshortestpath loop optimization

[casualwind]

Add a condition in the loop planner to judge whether there is any
independent subgraph of the vids. If it is true, then the loop ends.

What type of PR is this?

• [yes] bug
• feature
• enhancement

What problem(s) does this PR solve?

Issue(s) number:

close #4634

Description:

Early leave findshortestpath if the leftvid or the rightvid in a complete divided subgraph without the other one.
Early leave findshortestpath if one the destination vid or start vid doesnot exist.

How do you solve it?

Judge whether newer vids are added in the leftInputVar or the rightInputVar.
add the additional condition in the loop condition.

Special notes for your reviewer, ex. impact of this fix, design document, etc:

Checklist:

Tests:

• Unit test(positive and negative cases)
• Function test
• Performance test
• N/A

Affects:

• Documentation affected (Please add the label if documentation needs to be modified.)
• Incompatibility (If it breaks the compatibility, please describe it and add the label.）
• If it's needed to cherry-pick (If cherry-pick to some branches is required, please label the destination version(s).)
• Performance impacted: Consumes more CPU/Memory

Release notes:

Please confirm whether to be reflected in release notes and how to describe:

ex. Fixed the bug .....

[CLAassistant]

All committers have signed the CLA.

[Sophie-Xie]

@casualwind Thanks for contribution! pls sign the CLA and fix the fail of CI :)

[casualwind]

I have signed the CLA and fix the fail of CI

[casualwind]

@nevermore3 Do you have any time to take a look at this pr? is this blocked by the #4678? is there anything need me to follow up? Thank you.

[nevermore3]

LGTM, thanks for your contribution