Well completions refactoring

Refactor well completions module.

This PR uses new package with utility-function for @webviz/well-completions-plot, created after https://github.com/equinor/webviz-subsurface-components/pull/2251

Description

Refactor back-end:
- Replace pandas with polars
- Allow selection of realizations to include (for realization filtering in front-end).
- Refactor well_completions_access.py, split into two files:
  - well_completions_access.py for retrieving data from Sumo and returning resulting well completions data as single pyarrow pa.Table.
  - well_completions_assembler.py building well completions data structure from the pa.Table from Sumo.
Front-end:
- Add sorting of wells - utilizing new utility-lib from @webviz/well-completions-plot from webviz-subsurface-components
- Refactor settings.tsx code to utilize atoms for business-logic

Closes bulletin in: #711 Closes bulletin in: #695 Closes: #627

equinor / webviz