Add testing for CNV Evidence plots and tables

[kelseykeith]

While there are existing genes and cancer groups selected for TPM testing, those may not be the best genes to test the CNV API endpoints. So the existing genes need to be tested as to whether they make a good testing suite for CNVs or alternative genes need to be considered, like the genes used for the plot demos ADNP2, DUX4, IRS4, and MYCN. Due to the known common copy number alterations in MYCN in Neuroblastoma, it should probably be included regardless. Cancers known and not know for CNV alterations should also be included in the testing. Once genes and cancer groups are selected at a minimum the following code will be needed to add to tests/r_test_scripts/test_endpoint_http.R to add tests to the new endpoints:

    list(
      path = "/dna-methylation/gene-disease/plot",
      params = c("ensemblId", "efoId")),
    list(
      path = "/dna-methylation/gene-disease/json",
      params = c("ensemblId", "efoId")),