New study page API from mutation data counts

[kalletlak]

Related to cBioPortal/cbioportal#6759. Add new API to get mutations count based on gene, profile and StudyViewFIlter

API should support following options

Option 1: based on whether the sample is mutated or not

Mutated (the samples with one or more mutations in the gene)
Not mutated (the samples without mutations in the gene)
Not profiled (the samples that were not profiled)

Option 2: based on mutation type

mutation types and driver vs vus as defined in oncoprint
Not mutated (the samples without mutations in the gene)
Not profiled (the samples that were not profiled)