v2.9.0

## New features - Buy Crypto allows USDT (ERC20) and Stellar - Introducing a carousel on the portfolio tab - Added a get help section with useful links ## Fixes - Support new Stellar protocol and fixed memo field that was resetting when changing recipient - Decred app not detected as outdated anymore on desktop - Unification of Cosmos operations details - Cosmos/Tron UI uniformisation - Native SegWit comes first in the add account flow