feat(storage): add index to schema

[joseivanlopez]

Changes:

• Calculate initial proposal from a JSON config generated from the product data.
• Add index to the storage schema: it allows to detect which unsolved config correspond to each drive and/or partition. Changing a config (e.g., the size of a partition) will be easier thanks to the index too.
• Improve model to add information about auto sizes.
• Improve model to add information about resized partitions.

[coveralls]

Pull Request Test Coverage Report for Build 11800402213

Details

• 43 of 43 (100.0%) changed or added relevant lines in 14 files are covered.
• 2 unchanged lines in 1 file lost coverage.
• Overall coverage remained the same at 71.449%

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Files with Coverage Reduction	New Missed Lines	%
service/lib/agama/storage/config_conversions/to_json_conversions/volume_group.rb	2	89.66%

Totals
Change from base Build 11781949244:	0.0%
Covered Lines:	16937
Relevant Lines:	23705

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💛 - Coveralls

[ancorgs]

I'm just starting, but I admit I didn't expect to see the indexes on the schema. Feels like leaking an internal implementation detail.