By William James LONDON (Reuters) -Britain will begin negotiations on Tuesday to join a trans-Pacific trade deal that it sees as crucial to its post-Brexit pivot away from Europe and towards geographically more distant but faster-growing economies. The Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP) removes 95% of tariffs between its members: Japan, Canada, Australia, Vietnam, New Zealand, Singapore, Mexico, Peru, Brunei, Chile and Malaysia. Britain hopes to carve out a niche for itself in world trade as an exporter of premium consumer goods and professional servi...