refactor: rename fedb to OpenMLDB

[shiyoubun]

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)
  feature:
  Rename fedb to OpenMLDB in specific files.

[github-actions]

HybridSE Linux Test Report

       65 files       231 suites   5m 37s ⏱️
19 160 tests 19 160 ✔️ 0 💤 0 ❌

Results for commit b4bf2bc.

[github-actions]

HybridSE Mac Test Report

       65 files       231 suites   6m 41s ⏱️
19 160 tests 19 160 ✔️ 0 💤 0 ❌

Results for commit b4bf2bc.

[github-actions]

Linux Test Report

     112 files       238 suites   43m 40s ⏱️
  8 623 tests   8 620 ✔️ 3 💤 0 ❌
12 755 runs  12 752 ✔️ 3 💤 0 ❌

Results for commit b4bf2bc.

[codecov]

Codecov Report

Merging #1420 (b4bf2bc) into main (0279b70) will increase coverage by 0.01%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##               main    #1420      +/-   ##
============================================
+ Coverage     65.53%   65.55%   +0.01%     
  Complexity      236      236              
============================================
  Files           571      571              
  Lines        107038   107131      +93     
  Branches        859      859              
============================================
+ Hits          70148    70225      +77     
- Misses        36738    36754      +16     
  Partials        152      152              

Impacted Files	Coverage Δ
src/catalog/sdk_catalog.cc	73.40% <0.00%> (-1.07%)	⬇️
src/replica/log_replicator.cc	77.19% <0.00%> (-0.66%)	⬇️
src/sdk/sql_cluster_router.cc	38.79% <0.00%> (-0.21%)	⬇️
src/tablet/tablet_impl.cc	38.08% <0.00%> (-0.08%)	⬇️
src/nameserver/name_server_impl.cc	37.61% <0.00%> (-0.02%)	⬇️
src/cmd/openmldb.cc	0.00% <0.00%> (ø)
src/sdk/sql_router.h	33.33% <0.00%> (ø)
src/tablet/tablet_impl.h	100.00% <0.00%> (ø)
src/catalog/tablet_catalog_test.cc	96.99% <0.00%> (+0.14%)	⬆️
src/zk/zk_client.cc	83.19% <0.00%> (+0.27%)	⬆️
... and 8 more

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