Add potential CTNNB1 from msk-impact

[leexgh]

86 CTNNB1 variants, marked as pending.
Criterions:

• from https://cbioportal.mskcc.org/results/mutations?cancer_study_list=mskimpact&Z_SCORE_THRESHOLD=2.0&RPPA_SCORE_THRESHOLD=2.0&profileFilter=mutations%2Cstructural_variants%2Ccna&case_set_id=mskimpact_cnaseq&gene_list=CTNNB1&geneset_list=%20&tab_index=tab_visualize&Action=Submit
• filtered from X3_splice to X29_splice (our existing variants are from X1_splice to X29_splice so I filtered them until X29_splice, there are still some potential ones after X29_splice, but those are at the middle of exon3 and are too far from splice site, might need more checking before adding those)
• Remove existing reVUE variants
• Remove single-nucleotide change variants
• Only keep in frame