Adding logs and exception for ubi repo sets [RHELDST-11863]

[amcmahon-rh]

If the debug or source repo for an RPM repo was not present, the returned value was None, which caused an attribute exception since the code would try accessing values from None. This change checks to ensure these repos actually exist, and raises an exception if they're not present.

[rbikar]

run tests

[codecov[bot]]

Codecov Report

Base: 97.24% // Head: 97.25% // Increases project coverage by +0.00% :tada:

Coverage data is based on head (a2a9b2d) compared to base (921e5a2). Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #194 +/- ## ======================================= Coverage 97.24% 97.25% ======================================= Files 7 7 Lines 1053 1055 +2 ======================================= + Hits 1024 1026 +2 Misses 29 29 ``` | [Impacted Files](https://codecov.io/gh/release-engineering/ubi-population-tool/pull/194?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=release-engineering) | Coverage Δ | | |---|---|---| | [ubipop/\_\_init\_\_.py](https://codecov.io/gh/release-engineering/ubi-population-tool/pull/194/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=release-engineering#diff-dWJpcG9wL19faW5pdF9fLnB5) | `94.60% <100.00%> (+0.02%)` | :arrow_up: | Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=release-engineering). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=release-engineering)

:umbrella: View full report at Codecov.
:loudspeaker: Do you have feedback about the report comment? Let us know in this issue.

[rbikar]

run tests

[rbikar]

codecov will be fixed by https://github.com/release-engineering/ubi-population-tool/pull/195

[rbikar]

run tests

[rbikar]

run tests

[rbikar]

run tests

[rbikar]

run tests

[rbikar]

run tests

[rbikar]

run tests

[rbikar]

run tests

[rbikar]

Cant' get any results from Jenkins CI as the test suite fail on some errors related to environment -> overriding the requirement for this check and merging.