[ISSUE #8025] fix: fix topic route when topic deleted

[HScarb]

Which Issue(s) This PR Fixes

Fixes #8025

Brief Description

1. make getTopicRouteInfoFromNameServer return null when the topic not exist and allow the topic not exist
2. remove the topic from topicRouteTable when topic is null

How Did You Test This Change?

UT

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 42.80%. Comparing base (04dddec) to head (c8e1ef8).

Additional details and impacted files

@@              Coverage Diff              @@
##             develop    #8027      +/-   ##
=============================================
- Coverage      42.82%   42.80%   -0.02%     
- Complexity     10345    10350       +5     
=============================================
  Files           1270     1270              
  Lines          88677    88678       +1     
  Branches       11398    11398              
=============================================
- Hits           37973    37961      -12     
- Misses         46004    46017      +13     
  Partials        4700     4700              

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[github-actions[bot]]

This PR is stale because it has been open for 365 days with no activity. It will be closed in 3 days if no further activity occurs. If you wish not to mark it as stale, please leave a comment in this PR.

[github-actions[bot]]

This PR was closed because it has been inactive for 3 days since being marked as stale.