[feature] validate() should work for conan install

[mpusz]

validate() was advertised as a new solution that should replace configuration verification that was previously handled in the configure() method. However, it turns up that even though configure() properly triggers an error during conan install, validate() is not checked at all at this stage.

I personally think that such behavior is highly misleading and if possible validate() should be used to validate the configuration for all workflows (both package creation and package consumption).

Otherwise, the documentation should be very clear that configure() is the only possible way to verify a configuration error in the package consumption workflow.

• I've read the CONTRIBUTING guide.

[samuel-emrys]

Duplicate of #10602 - looks like this is slated for 1.47.0

[memsharded]

Thats right, lets continue on #10602