Inconsistent naming for io functions

[henrymartin1]

At the moment we have:

• read_positionfixes_csv
• read_positionfixes_postgis
• positionfixes_from_gpd
  So I would propose that we rename positionfixes_from_gpd to read_positionfixes_gpd

[svenruf]

I originally named it like this, but in a meeting the argument (don't remember from who) was that it isn't actually a reading function, as it does only import/rename the GeoDataFrame. So I changed the name 😄

[henrymartin1]

I think i can remember this 😬. I just tried using it and found it weird that it is named differently...

[henrymartin1]

We agreed on double checking if pandas makes a distinction between reading and loading if it is not external. If there is no distinction, then we can rename the function in read_positionfixes_gpd