Use Configurate or snakeyaml for yml parsing

[AuroraLS3]

I would like to be able to..

Split from #1363

Not use a custom yml parser (Leads to bugs #2297)

Is your feature request related to a problem? Please describe.

The previous ticket #1363 had unrelated stuff about moving to configurate in it. It is below

TODO

• Prepare for configurate
  • Extract interface from Config and ConfigNode, (keep implementation with classes LegacyConfig and LegacyConfigNode)
  • Extract interface from and rename ConfigReader and ConfigWriter to LegacyConfigReader and LegacyConfigWriter
• Write configurate based Config implementation
  • Add configurate as a dependency, shadow and relocate it
  • Implement ConfigNode and Config interfaces with configurate
  • Move everything that extends LegacyConfig to use ConfigurateConfig
    • Optional: If it is easier, change the configs to use composition instead of inheritance
  • Implement ConfigReader and ConfigWriter and writer for configurate.
  • Implement a ConfigReader and ConfigWriter that pass the read/write call to appropriate implementation
    • eg: If ConfigurateConfigReader fails to read the yml (Because it is not valid yml), read with LegacyConfigReader so that the modifications mentioned above can be applied.
    • eg: If Writer is passed a LegacyConfig it is written with LegacyConfigWriter

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Acceptance criteria

At the end of this following classes should exist:

• Config (interface)
• ConfigNode (interface)
• ConfigWriter
• ConfigReader
• LegacyConfig
• LegacyConfigNode
• LegacyConfigWriter
• LegacyConfigReader
• ConfigurateConfig
• ConfigurateConfigNode
• ConfigurateConfigWriter
• ConfigurateConfigReader
• _____ConfigReader (the reader that calls other readers)
• _____ConfigWriter (the writer that calls other writers)

Validations:

• Plan can enable with an old config (I think there is an unit test for this)
• Old config is transformed during enable
• Transformed yml is valid yml
• Config does not lose comments when using configurate
• Plan can enable with a new config without using LegacyConfig

[Vankka]

Config does not lose comments when using configurate

Won't be able to write files and have comments on yaml without SpongePowered/Configurate#175