[SR-15570] SymbolKit: Parse symbol kinds with a known language

[QuietMisdreavus]

Previous ID	SR-15570
Radar	None
Original Reporter	@QuietMisdreavus
Type	Improvement

Additional Detail from JIRA

Votes	0
Component/s	Swift-DocC
Labels	Improvement
Assignee	None
Priority	Medium

md5: a769a8f20a3a2a1a27d0ea7853785b56

Issue Description:

Currently, symbol kinds are parsed by comparing the kind string against a list of known symbol kinds, first as a whole and then with the first component discarded. However, this relies on the assumption that the first component of a symbol kind is a language identifier (e.g. `swift.func`). To prevent accidental loss of data, we should figure out a way to parse symbol kinds by taking their interface language into account.

The main problem here is the structure of the Decodable protocol: Each type's implementation is run in isolation, without taking into account the rest of the data being decoded. This will need to be handled somehow if we want to handle this.

[QuietMisdreavus]

@shahmishal This should be transferred to swift-docc-symbolkit.