EP3956321B1 - Process for Preparing Axitinib, Process for Purifying the Intermediate 2-((3-Iodo-1h-Indazol-6-Yl)thio)-N-Methylbenzamide, Process for Purifying Axitinib via the Axitinib Hcl Salt, Solid Form of the Axitinib Hcl Salt