Added unit tests

[rsamigullin]

Description

Improved code coverage for aks-app-routing-operator

Fixes # https://msazure.visualstudio.com/CloudNativeCompute/_workitems/edit/24677451/
Feature # (details)

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes - Added more unit tests
Provide instructions so we can reproduce - run go test./...

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[coveralls]

Pull Request Test Coverage Report for Build 5823298761

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+9.3%) to 87.445%

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Totals
Change from base Build 5798948450:	9.3%
Covered Lines:	1790
Relevant Lines:	2047

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💛 - Coveralls

[jaiveerk]

/ok-to-test sha=c1edcf5

[jaiveerk]

minor changes, lgtm otherwise

[OliverMKing]

/ok-to-test sha=f1c345f

[jaiveerk]

approving to unblock merging

[OliverMKing]

/ok-to-test sha=e6ef8db

[OliverMKing]

/ok-to-test sha=e8f17b5