Expand annotation style customization options

[leshane]

Summarize your feature idea. (Why)

Expand the customization options for annotation styles beyond just background color. Given the diverse characteristics of sequences represented by annotations, expanded customization options will make it possible for users to visually differentiate and categorize sequences with more clarity and precision.

Desired Features:

• Borders & Outlines: Allow users to customize border color and style (dashed, dotted, solid).
• Font Customization: Introduce options for font style, size, weight, and color.
• Gradient & Pattern Backgrounds: Instead of just solid background colors, allow for gradient fills or patterned backgrounds.

Out of scope

• Icons & Symbols: Provide the ability to attach specific icons or symbols next to or within annotations (Render an SVG in an annotation  #229).