Add send all amount button to send transaction form

[faival]

Expected behaviour

• The amount field should display a link/button "Set max. amount" on the right when focused and empty
• Once the amount field is not empty, the button is replaced with the USD/EUR conversion rate
• If the amount field is not focused and empty, then nothing is displayed on the right of it.
• Clicking the "Set max. amount" button fills in account balance minus 0.1 LSK fee.