Add Rattler based installer backend

[jaimergp]

Closes #157

For now I'm using a subprocess to not disrupt the whole QProcess machinery, but we could totally do this in-process if we wanted.

[psobolewskiPhD]

Any thought to releasing the rattler CI as its own thing? I mean it seems useful more broadly?

[jaimergp]

I started it as a private detail because I don't want external folks using it on their own and start suggesting an expansion of scope that increases our maintenance burden in the long run.

[jaimergp]

During the community call yesterday, Tim floated the idea of just having a declarative file with the requested plugins, and whether they come from conda or PyPI. I think it makes a lot of sense and simplifies our setup. I can work on this PR so it's not as imperative, buuut...

The only con I can think of is that any changes done to the environment will be lost if not collected in the declarative file, which might annoy power users.

[codecov]

Codecov Report

❌ Patch coverage is 76.12903% with 37 lines in your changes missing coverage. Please review.
✅ Project coverage is 93.48%. Comparing base (c6c473c) to head (2d91171).
⚠️ Report is 23 commits behind head on main.

Files with missing lines	Patch %	Lines
src/napari_plugin_manager/_rattler_installer.py	79.76%	17 Missing ⚠️
...napari_plugin_manager/base_qt_package_installer.py	70.00%	15 Missing ⚠️
src/napari_plugin_manager/qt_package_installer.py	37.50%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #171      +/-   ##
==========================================
- Coverage   94.48%   93.48%   -1.01%     
==========================================
  Files          14       15       +1     
  Lines        2159     2303     +144     
==========================================
+ Hits         2040     2153     +113     
- Misses        119      150      +31     

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[dalthviz]

Hi there, gave this a check and seems like this is missing the GUI part so users can select the rattler backend, right? Maybe adding an option in the tool/source combobox for rattler is missing or maybe it could be that rattler will eventually replace the direct usage of conda?

Tried giving this a check locally by making the conda option in the GUI to select the rattler tool value but seems like that is not enough to make the backend work. When trying to install a package I got the following output/error:

Starting 'C:\Users\dalth\anaconda3\envs\napari-plugin-manager-dev\python.exe' with args ['-m', 'napari_plugin_manager._rattler_installer', '--action', 'install', '--prefix', 'C:\\Users\\dalth\\anaconda3\\envs\\napari-plugin-manager-dev', '--channel', 'conda-forge', 'affinder==0.5.0']
Traceback (most recent call last):
  File "C:\Users\dalth\anaconda3\envs\napari-plugin-manager-dev\lib\runpy.py", line 196, in _run_module_as_main

    return _run_code(code, main_globals, None,
  File "C:\Users\dalth\anaconda3\envs\napari-plugin-manager-dev\lib\runpy.py", line 86, in _run_code
    exec(code, run_globals)
  File "E:\Acer\Documentos\Quansight\Napari\napari-plugin-manager\src\napari_plugin_manager\_rattler_installer.py", line 196, in <module>
    sys.exit(asyncio.run(main()))
  File "C:\Users\dalth\anaconda3\envs\napari-plugin-manager-dev\lib\asyncio\runners.py", line 44, in run

    return loop.run_until_complete(main)
  File "C:\Users\dalth\anaconda3\envs\napari-plugin-manager-dev\lib\asyncio\base_events.py", line 649, in run_until_complete
    return future.result()
  File "E:\Acer\Documentos\Quansight\Napari\napari-plugin-manager\src\napari_plugin_manager\_rattler_installer.py", line 152, in main
    records, requested = await solve_records(
  File "E:\Acer\Documentos\Quansight\Napari\napari-plugin-manager\src\napari_plugin_manager\_rattler_installer.py", line 115, in solve_records
    return await rattler.solve(
  File "C:\Users\dalth\anaconda3\envs\napari-plugin-manager-dev\lib\site-packages\rattler\solver\solver.py", line 85, in solve
    for solved_package in await py_solve(
exceptions.SolverException: Cannot solve the request because of: No candidates were found for none *.


Task finished with exit code 1 with status 0.