Use the path of URL instead of query parameter for static sub tabs

[onursumer]

We use query variables to route to certain static sub tabs.

For example:

• comparison_subtab in https://www.cbioportal.org/results/comparison?cancer_study_list=ov_tcga_pub...&comparison_subtab=survival
• pathways_source in https://www.cbioportal.org/results/pathways?cancer_study_list=ov_tcga_pub...&pathways_source=NDEx

Ideally we should handle this in the path of URL instead.

So for comparison tab we would have a URL like https://www.cbioportal.org/results/comparison/survival?cancer_study_list=ov_tcga_pub... and for pathways tab we would have https://www.cbioportal.org/results/pathways/ndex?cancer_study_list=ov_tcga_pub... instead.

See previous discussion here.