Fixed ibrareader to return a unique_ptr #32

[codecov[bot]]

Codecov Report

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

Comparison is base (1b971f1) 92.52% compared to head (d057c6a) 92.60%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #35 +/- ## ========================================== + Coverage 92.52% 92.60% +0.08% ========================================== Files 31 31 Lines 3852 3856 +4 Branches 62 62 ========================================== + Hits 3564 3571 +7 + Misses 243 240 -3 Partials 45 45 ``` | [Flag](https://app.codecov.io/gh/rath3t/dune-iga/pull/35/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Alex_Mueller) | Coverage Δ | | |---|---|---| | [tests](https://app.codecov.io/gh/rath3t/dune-iga/pull/35/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Alex_Mueller) | `92.60% <100.00%> (+0.08%)` | :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=Alex_Mueller#carryforward-flags-in-the-pull-request-comment) to find out more. | [Files](https://app.codecov.io/gh/rath3t/dune-iga/pull/35?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Alex_Mueller) | Coverage Δ | | |---|---|---| | [dune/iga/io/ibra/ibrareader.hh](https://app.codecov.io/gh/rath3t/dune-iga/pull/35?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Alex_Mueller#diff-ZHVuZS9pZ2EvaW8vaWJyYS9pYnJhcmVhZGVyLmho) | `94.02% <100.00%> (+4.47%)` | :arrow_up: | | [dune/iga/test/trimmedGridTests.cc](https://app.codecov.io/gh/rath3t/dune-iga/pull/35?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Alex_Mueller#diff-ZHVuZS9pZ2EvdGVzdC90cmltbWVkR3JpZFRlc3RzLmNj) | `97.99% <100.00%> (+0.02%)` | :arrow_up: |

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