Fixes: admin notices displaying incorrectly, basic admin CSS, options page H2

- Separated `.wrap` and `.titan-framework-panel-wrap` divs to prevent admin notices displaying inside Titan panel.
- Moved the options page H2 element to display inside `.wrap`, but outside `.titan-framework-panel-wrap` for the same reason.
- Removed logic to display tab title inside H2 in favor of simply displaying the main options panel title, which matches standard plugin and theme behavior.
- Modified admin CSS to remove unnecessary `.wrap` selectors and background/border from the main .titan-framework-panel-wrap div.