EGFR and urothelial carcinoma: EGFR-Mutant Urothelial Carcinoma Harboring an Ala750_Ile759delinsGlyGly Alteration with a Primary Resistance to Polychemotherapy and a Sensitivity to Osimertinib: A Literature Review on EGFR Alterations and Response to EGFR Tyrosine Kinase Inhibitors in Cancers