qt: Handle fonts of deleted widgets properly, streamline the flow in `GUIUtil::updateFonts` (#3772)
qt: Handle fonts of deleted widgets properly, streamline the flow in `GUIUtil::updateFonts` (#3772)

* Refactor and fix `GUIUtil::updateFonts`

Use QPointer-s to process deleted widgets properly, streamline the flow (less loops and map scans).

* Add some debug output

* qt: Rename mapNormalFontUpdates -> mapFontUpdates

The "Normal" was added when we also had other maps containing font updates

* qt: Count removed items, adjust debug logs

* qt: Use the emplace result for the default font size

* qt: Perform all widget font updates later in a seperate step

* qt: Drop pointSize checks

* qt: Refactor app class font scaling

Co-authored-by: xdustinface <8d97cd3e673c5c36814dfffedf1e57d40cb95336@gmail.com>
thelazier/dash,dashpay/dash,UdjinM6/dash,thelazier/dash,dashpay/dash,UdjinM6/dash,dashpay/dash,UdjinM6/dash,dashpay/dash,dashpay/dash,thelazier/dash,thelazier/dash,UdjinM6/dash,thelazier/dash,UdjinM6/dash