[enh] Menu: better layout for large screen

[enh] Help tour: adapt tour to the new menu layout (start with wallet, tx, etc.)
[enh] Wallet QRCode: faster animation, when click on a QRCOde
[enh] Wallet: better explanation in Cesium+ help icon, with new link to Cs+ network view
[fix] profile: store HTML description inside a new attribute, to avoid saving it
[fix] Locale flag: use local image file
[fix] Locale flag: add EO flag - fix #887
[fix] Settings: enable cache persitence option, in small device