Release version 0.23.6

[JiriPavela]

• Fix issue with empty CLI stats headers
• Implement lazy loading of the most expensive internal packages to speedup Perun and make CLI snappier

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 98.96%. Comparing base (2ec3930) to head (fa10e84). Report is 2 commits behind head on devel.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## devel #261 +/- ## ======================================= Coverage 98.96% 98.96% ======================================= Files 158 158 Lines 10812 10812 ======================================= Hits 10700 10700 Misses 112 112 ``` | [Flag](https://app.codecov.io/gh/Perfexionists/perun/pull/261/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Perfexionists) | Coverage Δ | | |---|---|---| | [coverage-3.10](https://app.codecov.io/gh/Perfexionists/perun/pull/261/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Perfexionists) | `98.95% <ø> (-0.01%)` | :arrow_down: | | [coverage-3.11](https://app.codecov.io/gh/Perfexionists/perun/pull/261/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Perfexionists) | `98.96% <ø> (ø)` | | | [coverage-3.12](https://app.codecov.io/gh/Perfexionists/perun/pull/261/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Perfexionists) | `98.95% <ø> (ø)` | | | [coverage-3.9](https://app.codecov.io/gh/Perfexionists/perun/pull/261/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Perfexionists) | `98.93% <ø> (ø)` | | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Perfexionists#carryforward-flags-in-the-pull-request-comment) to find out more.

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.