Merge #17360: gui: Improve "Hide" button tool-tip message

1c26c16 Improve "Hide" button tool-tip message (Danny-Scott)

Pull request description:

  Cleaned up the tool tip text, it looks as though it just got included back in 2014 when the whole section was added.

  Changed hide button tool tip within transaction fee settings area from "collapse fee-settings" to "Hide transaction fee settings" to be more user friendly and fit with other tool tips.

  ![hide-transaction-fee-tool-tip](https://user-images.githubusercontent.com/17258195/68086415-b7b70680-fe43-11e9-82cb-567b9730c1b9.png)

ACKs for top commit:
  laanwj:
    ACK 1c26c16

Tree-SHA512: e2c83271c273f785ac625da9f88e095076043e21a9c59792049c271747837d19483e0cae5466c26ef3231947b6245680c4c136a530ba6f1885f9ddc18f2560d6

Author: laanwj

src/qt/forms/sendcoinsdialog.ui

@@ -797,7 +797,7 @@
           <item>
            <widget class="QPushButton" name="buttonMinimizeFee">
             <property name="toolTip">
-             <string>collapse fee-settings</string>
+             <string>Hide transaction fee settings</string>
             </property>
             <property name="text">
              <string>Hide</string>