chore: increase test coverage

[cristianIOHK]

Description:

This PR increases the number of unit tests to improve the code coverage.

Checklist:

• My PR follows the contribution guidelines of this project
• My PR is free of third-party dependencies that don't comply with the Allowlist
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• I have checked the PR title to follow the conventional commit specification

[github-actions]

Unit Test Results

141 tests  +32   138 ✅ +32   7s ⏱️ ±0s
 25 suites + 1     3 💤 ± 0 
 25 files   + 1     0 ❌ ± 0 

Results for commit 754808f. ± Comparison against base commit 8bdb59b.

♻️ This comment has been updated with latest results.

[coveralls]

Pull Request Test Coverage Report for Build 10324495092

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 25 unchanged lines in 1 file lost coverage.
• Overall coverage increased (+0.9%) to 43.907%

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Files with Coverage Reduction	New Missed Lines	%
org/hyperledger/identus/walletsdk/pluto/PlutoImpl.kt	25	70.62%

Totals
Change from base Build 10288062413:	0.9%
Covered Lines:	3080
Relevant Lines:	6103

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💛 - Coveralls