[Qt] re-work overviewpage UI

- ensure normal and watch-only stuff looks consistent
- simplify UI by removing unneeded UI layout elements
- change some comments to watch-only from watchonly
Merge pull request #4627

94e1b9e [Qt] re-work overviewpage UI (Philip Kaufmann)
[Qt] move SubstituteFonts() above ToolTipToRichTextFilter

- doesn't belong to the ToolTipToRichTextFilter class so move it up