feat(flow): flow node addr key

[discord9]

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Refer to a related PR or issue link (optional)

#4094

What's changed and what's your intention?

add a key to store mapping from flownode id to addr

Please explain IN DETAIL what the changes are in this PR and why they are needed:

• Summarize your change (mandatory)
  added a mapping from flownode id to flownode addr, so that in distributed mode can flownode be registered and discover(which will be in a subsequent PR)

Checklist

• I have written the necessary rustdoc comments.
• I have added the necessary unit tests and integration tests.
• This PR requires documentation updates.

[codecov]

Codecov Report

Attention: Patch coverage is 50.70423% with 35 lines in your changes missing coverage. Please review.

Project coverage is 84.86%. Comparing base (ea2d067) to head (6cd958c).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4164      +/-   ##
==========================================
- Coverage   85.16%   84.86%   -0.31%     
==========================================
  Files        1021     1022       +1     
  Lines      179241   179311      +70     
==========================================
- Hits       152650   152169     -481     
- Misses      26591    27142     +551     

[fengjiachun]

I'm working on this in #4166.

[discord9]

Close for #4166