Group properties - simplify import process

[shawnlaffan]

Attaching group properties can be a cumbersome process.

Data are imported as a basedata, stats calculated, results exported to CSV, and then attached.

This can be done in a single pass, optionally adding the interim basedatas to the project when under the GUI.

To do:

• Basic code
• GUI
• Add basedatas to project
• Handle duplicate names - or just overwrite as that's simpler. Update: We overwrite as that's consistent with other property methods where duplicates are encountered.
• Check extents match. Users might try data with different coordinate systems that cannot overlap. Warn if one or two mismatches, croak if many. Edit: make it configurable as a boolean arg
• Use a def query to speed up analyses. Target basedata might be a very small subset of the property raster, for example global data from Worldclim being applied to a basedata of Indonesian plants. Def query can be the intersection of the extents. Moved to separate issue in raster imports: Use a def query to constrain imports #805
• Throw exceptions on non-raster files - needs tests
• Blog post - https://biodiverse-analysis-software.blogspot.com/2022/05/importing-group-properties-directly.html

[shawnlaffan]

All tasks have been completed or hived off to their own issues. Mark as fixed.