Fix connection parameter handling

[pnuu]

In #165 S3FileSystem() were given all the "extra" kwargs given to the class. For Dispatcher this was only connection_parameters, but for Trollmoves Server this is the full configuration file. The kwarg handling in S3FileSystem and aiobotocore.core.AioSession are such that the values not consumed by the former are passed to the latter. This caused unrecognized kwargs from the Trollmoves Server config being passed to AioSession and as it doesn't have a catch-all **kwargs they cause it to crashed.

This PR changes the config handling in the following way:

• Dispatcher passes the full config to trollmoves.movers.move_it()
• S3Mover.copy() gets the dictionary connection_parameters and passes it's items to S3FileSystem()
• dictionaries can be given in Trollmoves Server .ini configuration

Note that numeric values given in the nested dictionary are not handled.

• Closes S3 mover passes all config items to S3FileSystem() #189
• Tests added
• Fully documented

[codecov]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (6e77ed1) 90.98% compared to head (e158f3a) 91.05%.
Report is 2 commits behind head on main.

Files	Patch %	Lines
trollmoves/server.py	97.14%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #190      +/-   ##
==========================================
+ Coverage   90.98%   91.05%   +0.06%     
==========================================
  Files          24       24              
  Lines        5247     5298      +51     
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+ Hits         4774     4824      +50     
- Misses        473      474       +1     

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unittests	91.05% <98.21%> (+0.06%)	⬆️

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[mraspaud]

S3Mover is unfortunately not the only place where the connection parameters are used, eg the ScpMover also uses this. It is though not tested, so we can't see it from the CI, but these changes very likely break it.
Also, it feels backwards to pass the full config to the movers when only the connection parameters are needed. Instead, I think we need to modify the move_it_server to only pass the connection parameters to the movers.
Or is there a use case I missed when the full config is needed by the movers?

[pnuu]

S3Mover is unfortunately not the only place where the connection parameters are used, eg the ScpMover also uses this. It is though not tested, so we can't see it from the CI, but these changes very likely break it.

ScpMover does not use connection_parameters dictionary. It was actually only Dispatcher that collected this dictionary and passed it to the movers as extra kwargs whereas Trollmoves Server passes the whole config.

Also, it feels backwards to pass the full config to the movers when only the connection parameters are needed. Instead, I think we need to modify the move_it_server to only pass the connection parameters to the movers. Or is there a use case I missed when the full config is needed by the movers?

In Trollmoves Server we've never had the connection parameters, which is a dictionary, because it uses ini configs. Thus all the items are in the main level of the configuration. Putting these various connection related items in a dictionary would need special item-by-item handling when combining them from the config.

[pnuu]

Adjusted based on a short discussion on Slack huddle.

[mraspaud]

Looks good! just a couple of comments.

[mraspaud]

should we have a deprecation warning here? to motivate people to move to the __ syntax?

[pnuu]

Hmm. Maybe 🤔 I'll see think about this and see how to document this in the first place.

[pnuu]

Warning added in e158f3a

[mraspaud]

shouldn't we be passing only the connection parameters here?

[pnuu]

Oh, right. Forgot to revert this part, done in 53a4bc3

[mraspaud]

LGTM