Support Language interoperability

[jacktasia]

Generic support for jumping between different languages that can be part of the same project and call one another.

Examples:

java<->kotlin erlang<->elixir swift<>-objc

[netromdk]

Should dumb-jump then detect what languages are used in the file automatically or does the user need to hint somehow? If it detects used languages then it's not enough with a random order: If you're in some ObjC code it shouldn't try to jump as Swift code instead. I like the general idea though.

[kschwarz1116]

Something else that likely falls into this category is Scala and Scala Play Templates (.scala.html files). Willing to look into making a change if you have a general idea of how to go about it.