style: rename local hub settlement to local instead of mock

[mtsitrin]

to avoid compatibility issues, I've left it as "mock" in the configuration files.

On the source code, the local hub and local da are now called local instead of mock.

PR Standards

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• Wrote unit and integration tests
• All CI checks have passed
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[codecov]

Codecov Report

Attention: Patch coverage is 31.25000% with 11 lines in your changes are missing coverage. Please review.

Project coverage is 44.04%. Comparing base (9733e1c) to head (c042bc0).

Files	Patch %	Lines
da/celestia/mock/server.go	0.00%	6 Missing ⚠️
da/grpc/mockserv/mockserv.go	0.00%	5 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #628   +/-   ##
=======================================
  Coverage   44.04%   44.04%           
=======================================
  Files         120      120           
  Lines       16531    16531           
=======================================
  Hits         7281     7281           
  Misses       8219     8219           
  Partials     1031     1031           

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