grass.script: add create_project() with same functionality as create_location()

[chaedri]

As we begin renaming location to project, it would be nice to have a create_project() function that works the same as create_location.

This is particularly nice in notebooks because these function work without an active GRASS session so users can use a work flow that I think is very intuitive:

1. import grass.script and grass.jupyter
2. create_project() to make a new project
3. gj.init() to start the session in the new project

This PR also includes additional path support. For example, all the following lines will create a new project:

# just project name (creates project in current working directory)
gs.create_project("nags_head", epsg="32119") 

# grassdata path and name of project
gs.create_project("~/grassdata", name="nags_head", epsg="32119") 

# full path to new project
gs.create_project("~/grassdata/nags_head", epsg="32119") # full path to new project

[veroandreo]

This is a nice addition! Works as expected, at least in the tests I did :)

[echoix]

I approve the concept, read through it, but I'm leaving reviewing the fine details for someone else. I'm not confident enough in the implications, or if there is something missing with in regards to the transition to "project".

[wenzeslaus]

Ultimately, we need to have something like resolve_mapset_path but oriented towards project, specifically. However, at this point, this is the best implementation.

Given the need to support the two different API, a test would be helpful here to check that the different combinations of parameters work. It also seems that a test for existing project is missing.

[chaedri]

Given the need to support the two different API, a test would be helpful here to check that the different combinations of parameters work. It also seems that a test for existing project is missing.

I added two more tests, one that tests providing the full path (i.e. gs.create_project("~/grassdata/nags_head", epsg="32119") and one that tests create_project directly.

completed