test(sdk): mock attestation server.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 89.94975% with 20 lines in your changes are missing coverage. Please review.

Project coverage is 89.64%. Comparing base (118fd8f) to head (3b1bccc). Report is 2 commits behind head on main.

Files	Patch %	Lines
cmd/wallet-sdk-gomobile/attestation/client.go	89.74%	4 Missing and 4 partials :warning:
pkg/attestation/attestation_client.go	93.81%	3 Missing and 3 partials :warning:
pkg/internal/httprequest/httprequest.go	0.00%	6 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #738 +/- ## ========================================== - Coverage 89.69% 89.64% -0.05% ========================================== Files 101 104 +3 Lines 4211 4404 +193 ========================================== + Hits 3777 3948 +171 - Misses 286 301 +15 - Partials 148 155 +7 ```

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[sonarcloud[bot]]

Quality Gate passed

Issues
15 New issues

Measures
0 Security Hotspots
No data about Coverage
8.9% Duplication on New Code

See analysis details on SonarCloud