goolx: FindRelayGroup, FindLine, FindXFMR, etc.

[readpe]

Implement methods to find specific equipment given unique input parameters such as bus name, kv, and circuit id.

[readpe]

See for example:

OlxAPILib.BranchSearch
OlxAPILib.BusSearch

[readpe]

Implemented methods in ca7f981:

• FindBranch
• FindLine
• GetLine
• GetBus