[SLP] Auto-name after double-click new token.

This was already handled when the user would right-click->Add Token,
but double-clicking would not autofill the token's wallet name.  I also
changed the text from "right-click to add" to "double-click to add" for
newly received tokens.

RELEASE-NOTES

@@ -111,6 +111,7 @@ Electron Cash - SLP Token Edition
 - Other bug fixes including: SLP fee calculations improved, incorrect password after completing token creation would cause crash
 - Use separate change addresses in transactions having both BCH and SLP change when possible
 - Auto-detect receipt of Genesis minting batons or coins
+- Auto-name newly received tokens within Add Token Dialog after double-click (this was already implemented for right-click > Add token)
 - Disable change address options in preferences
 - Allow OP_RETURN entry in SLP wallets, but disable when a token is selected
 - Reordered Send Tab amount input fields and moved token selector above amount inputs

gui/qt/slp_mgt.py

@@ -78,7 +78,10 @@ def on_doubleclick(self, item, column):
             self.editItem(item, column)
         else:
             token_id = item.data(0, Qt.UserRole)
-            SlpAddTokenDialog(self.parent, token_id_hex = token_id, token_name=item.text(1) )
+            if('unknown-' in item.text(1)):
+                SlpAddTokenDialog(self.parent, token_id_hex = token_id, allow_overwrite=True)
+            else:
+                SlpAddTokenDialog(self.parent, token_id_hex = token_id, token_name=item.text(1))
 
     def create_menu(self, position):
         menu = QMenu()
@@ -138,7 +141,7 @@ def on_update(self):
                 balancestr = format_satoshis_nofloat(calculated_balance, decimal_point=decimals, num_zeros=decimals)
                 balancestr += ' '*(9-decimals)
             else:
-                balancestr = "right-click to add"
+                balancestr = "double-click to add"
 
             try:
                 self.parent.wallet.get_slp_token_baton(token_id)