Add Solarized Light and Dark themes

Summary: This adds Solarized Light and Dark themes, with the same color scheme selected in Phabricator diff D15337. This includes the themes here in KSyntaxHighlighting for when KTextEditor themes are replaced.

Reviewers: Kate, Framework: Syntax Highlighting, dhaumann

Reviewed By: Kate, Framework: Syntax Highlighting, dhaumann

Subscribers: dhaumann, kwrite-devel, kde-frameworks-devel

Tags: Kate, Frameworks, Framework: Syntax Highlighting

Differential Revision: https://phabricator.kde.org/D15340