Batch sendview

• implementation of the multitransaction views as specified here https://marvelapp.com/prototype/ff9bh0h/screen/75652103
• button to add a transfer to current batch in Send view
• Batch list button to send view to check the current batch
• Batch view showing the current batch
• Batch version of operation+signing summary
• Handle correctly(-ish) advanced options during batch
• Check fees sum is the right one
• Delete and Edit transfer in batch