ENH: Added temporal, engineering, and parametric datum PJ_TYPE enumerations

[snowman2]

• Closes Basic Temporal Datum Support (c-api) #2273
• Tests added
• Added clear title that can be used to generate release notes
• Fully documented, including updating docs/source/*.rst for new API

[snowman2]

@rouault there is the generic DATUM type. Is there a datum type that isn't covered by this that might pop up?

[snowman2]

Any chance of adding this in 7.1?

[kbevers]

Any chance of adding this in 7.1?

Not unless there's an RC3 - this PR in itself is not enough to trigger that.

[snowman2]

Not unless there's an RC3 - this PR in itself is not enough to trigger that.

From the perspective of pyproj, it is definitely worth it. 7.1 is the minimum version for the next release. It is a change that will address some current bugs.🤞

[snowman2]

It is a change that will address some current bugs.

I guess we could export each object to PROJ JSON and check the type there if this isn't added in 7.1 ... not quite as nice of a solution, but it works.

[rouault]

@kbevers Is this material for 7.1.1 backport ? asking since it extends the API

[kbevers]

asking since it extends the API

Then no. A very similar situation is adressed in this SO post: https://stackoverflow.com/questions/27300561/does-adding-enumerators-into-enum-break-abi/