Sprint/filedicts/class constructor

[pgierz]

There are far more commits in this PR than I know what to do with.

The last one is important. You can know build a simulation file in a few different ways:

>>> from esm_runscripts import filedicts
>>> paths = {"computer": "/some/nice/location", "exp_tree": "/some/other/nice/location"
>>> name = "My Beautiful File"
>>> sim_file = filedicts.SimulationFile(paths=paths, name=name)

Alternatively, you can just give the config and location in the config:

>>> from esm_runscripts import filedicts
>>> sim_file = filedicts.SimulationFile.from_config(path_to_config, "echam.files.jan_surf")

There is also introduced a DatedSimulationFile, which knows about its date.

There may be some duplication of mini fixes also in #922 (grammar in the comments) which I did not bother to filter out nicely.

[pgierz]

#approve-changes