Split up cdcl_sat::clause code out of cdcl_sat.hpp

[codecov[bot]]

Codecov Report

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

Comparison is base (7081c9d) 96.31% compared to head (c30105d) 96.25%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #31 +/- ## ========================================== - Coverage 96.31% 96.25% -0.06% ========================================== Files 20 23 +3 Lines 1574 1576 +2 Branches 1145 1144 -1 ========================================== + Hits 1516 1517 +1 + Misses 11 8 -3 - Partials 47 51 +4 ``` | [Flag](https://app.codecov.io/gh/michael-veksler/solver/pull/31/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Michael+Veksler) | Coverage Δ | | |---|---|---| | [Linux](https://app.codecov.io/gh/michael-veksler/solver/pull/31/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Michael+Veksler) | `61.13% <ø> (+0.04%)` | :arrow_up: | | [Windows](https://app.codecov.io/gh/michael-veksler/solver/pull/31/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Michael+Veksler) | `99.34% <ø> (ø)` | | | [macOS](https://app.codecov.io/gh/michael-veksler/solver/pull/31/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Michael+Veksler) | `35.96% <ø> (+0.02%)` | :arrow_up: | 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=Michael+Veksler#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.