Rename angularX configuration option to angular

[qmonmert]

Fix #19354

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[mshima]

Tagging as major since jdl will break with angularX value.

[JusticeN]

For backward compatibility it will be better to allow both angular and angularx for now. Update the documentation and and show warning when used. Then completely remove angularx in a later version

[DanielFran]

@JusticeN The target is for v8

[Tcharl]

Thus is it possible to create the V8 branch?

[mraible]

This PR needs a rebase.