Settings UI Improvements

[zacker150]

This PR updates the settings dialog

Related Discussions/Issues

• 265

• 267

Changes:

• Standardized font size to 10
• Better names for categories.
• Replaced List view with dropdown menu in Download Defaults page.
• Split tooltip settings into two columns (it was forcing the settings panel to expand)
• Update Imgur language
• Made color_groupbox checkable
• Update download defaults description
• Do not change the sample post user/subreddit name when switching lists

Before:

After: