[IMPROVEMENT] Enums for "external" components #315
Description
As pointed out in #295 (comment), some of the component type names in other libraries, such as in pandapower, are different to the names used in the power-grid-model. For this reason, it would be good practice to create Enums, similar to what was done in PowerGridModel/power-grid-model#648 for the power-grid-model component types and implemented in power-grid-model-io in #295, to keep track of the component types used in the libraries we convert from/to, as well as to keep reducing raw strs.
This may not directly affect the user, but will definitely keep the code implementation cleaner, and also help keeping track of what elements come from other libraries we convert to/from.