Set names when reading LISI CSV files

[lazappi]

Set names when reading the CSV files produced by C++ code in the LISI functions so that pandas knows how many columns to expect.

Fixes #374 (hopefully, but could do with some more testing)

[codecov[bot]]

Codecov Report

Merging #380 (2d6a3b9) into main (cce7aaa) will increase coverage by 0.02%. The diff coverage is 100.00%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #380 +/- ## ========================================== + Coverage 53.26% 53.29% +0.02% ========================================== Files 22 22 Lines 1851 1852 +1 ========================================== + Hits 986 987 +1 Misses 865 865 ``` | Flag | Coverage Δ | | |---|---|---| | unittests | `53.29% <100.00%> (+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=theislab#carryforward-flags-in-the-pull-request-comment) to find out more. | [Impacted Files](https://codecov.io/gh/theislab/scib/pull/380?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=theislab) | Coverage Δ | | |---|---|---| | [scib/metrics/lisi.py](https://codecov.io/gh/theislab/scib/pull/380?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=theislab#diff-c2NpYi9tZXRyaWNzL2xpc2kucHk=) | `42.28% <100.00%> (+0.15%)` | :arrow_up: |