Fix generation of idedata

[bjsowa]

Fixes #32 .
I wrote this PR only to demonstrate the problem, not to provide the best solution.
AFAIK, running pio init --ide <ide name> runs the idedata target to generate idedata.json file which contains information about include paths, defines etc. which is used to generate IDE-specific configuration files.
Currently the extra_script.py completely ignores the idedata target. This was done to avoid building the library when IDE fetches project metadata.
I think the script should instead update some of the environments (probably the global_env and projenv) regardless of the target name.

[bjsowa]

@pablogs9 @Acuadros95 Could you look at that?

[Acuadros95]

Currently the extra_script.py completely ignores the idedata target. This was done to avoid building the library when IDE fetches project metadata.
I think the script should instead update some of the environments (probably the global_env and projenv) regardless of the target name.

Agree, I have tested it and your fix looks OK.

Thanks for the contribution!