Harden & deliver dark theme

[nicolethoen]

in core:

• [x] patternfly/patternfly#5523

• [ ] Custom colors
• [ ] Inline alert https://github.com/patternfly/patternfly/issues/5501
• [ ] Horizontal nav
• [ ] Alert - info variant contrast (2 different blues)
• [ ] Banner - modifier names need to be updated (danger vs red etc)
• [ ] Brand - fix brand image not to hard code the fill color and/or add dark/light version. Also visible in card examples
• [ ] Breadcrumb divider - adjust color (should be resolved by updating static icon color, existing issue)
• [ ] Selectable/clickable cards need dark theme overrides
• [ ] Code editor readonly version - Monaco editor has its own styling for dark theme so this is different in react. Address the gray border indicating read only
• [ ] Drag and drop drag state/disabled state
• [ ] Dual list contrast in the disabled state/disabled controls - update to more legible disabled item, but leave the control as the existing plain disabled action
• [ ] Menu toggle split disabled state and icon are the same color
• [ ] Application launcher hover state color
• [ ] Application launcher favorites background color behind icons
• [ ] Disabled states in general have some inconsistencies (dual list, tabs, ?)
• [ ] Search highlighting - highlight color needs to be chosen for dark theme

core followup: - [ ] Update dark theme stylesheets to use theme-able variables rather than hardcoded variables

in org:

• [x] https://github.com/patternfly/patternfly-org/issues/3372
  • above issue will include updating styles and overrides in org to consume dark theme
• [x] patternfly/patternfly-org#3514
• [ ] Implement ability to swap out images when website switched to dark theme (nice to have)
• [ ] Update images (community page, design guidelines, etc) to include a dark theme version (nice to have)

in extensions:

• [x] patternfly/react-topology#49
• [x] patternfly/patternfly-extension-issues#50
• [ ] Address outstanding dark theme issues identified during audit