Fixing a few issues with the title editor

[jonoomph]

1. font-size was not being initialized on the font dialog, and
2. font-size was not being set (even though it can clobber our template settings
3. Not all text colors were being found when loading an SVG and setting the 'text-color' button

Overall, this fixes some of the broken behavior, but there are still a few outstanding issues with the title editor. Not all fonts are rendered on Windows for starters, often, it falls back to a default font. Not sure if this is caused by resvg, but seems likely.

[jonoomph]

Merging to do some daily build testing with a couple users

[ferdnyc]

Not sure if this is caused by resvg, but seems likely.

See linebender/resvg#297.

[ferdnyc]

@jonoomph

Since this change, I'm getting a ton of this when running with --debug:

DEBUG title_editor: Failed to parse fill:#6f82c1 as opacity value
DEBUG title_editor: Failed to parse fill:#6f82c1 as opacity value
DEBUG title_editor: Failed to parse fill:#6f82c1 as opacity value
DEBUG title_editor: Failed to parse fill:#6f82c1 as opacity value
DEBUG title_editor: Failed to parse fill:#6f82c1 as opacity value
DEBUG title_editor: Failed to parse fill:#6f82c1 as opacity value
DEBUG title_editor: Failed to delete child settings widget
DEBUG title_editor: Failed to parse fill:#324da7 as opacity value
DEBUG title_editor: Failed to parse fill:#6f82c1 as opacity value
DEBUG title_editor: Failed to parse fill:#324da7 as opacity value
DEBUG title_editor: Failed to parse fill:#6f82c1 as opacity value
DEBUG title_editor: Failed to delete child settings widget
DEBUG title_editor: Failed to parse fill:url(#radialGradient3654) as opacity value
DEBUG title_editor: Failed to parse fill:url(#radialGradient3654) as opacity value
DEBUG title_editor: Failed to delete child settings widget
DEBUG title_editor: Failed to parse fill:#ffffff as opacity value
DEBUG title_editor: Failed to parse fill:#ffffff as opacity value