add page parameters to api endpoints

[jjgao]

We need an api to determine whether alignments exists at all for a given transcript so that we don't have to pull all alignments just to determine that.

After discussion, we would like to add pagination pagination similar to what we do in cBioPortal API.

An empty list should be return if no alignments in the result.

Please add the following parameters similar to cBioPortal endpoints:

If it's too much work to add to all, please start with /api/alignments/{id_type}/{id} which is used by cBioPortal.

[juexinwang]

I will start working on that.

[jjgao]

Thanks, @juexinwang. We are discussing whether it's better to create the new endpoint or just add pagination to the api in the #genomenexus channel on slack.

[jjgao]

@juexinwang I updated the issue description above. Please let me know if you have any questions.