Modify Button component variants

[IsaDavRod]

Modify the existing button component to add new variants minimal/small, proper gap and padding using our new spacing system.

#464 PR implemented the spacing token system. It essentially ensures padding/margins between edges or elements are using consistent values. Read more about the 4px grid system.

src/shared/types/Spacing.ts

export const spacing = {
    'spacing-1': '.125rem',
    'spacing-2': '.25rem',
    'spacing-3': '.5rem',
    'spacing-4': '.75rem',
    'spacing-5': '1rem',
    'spacing-6': '1.25rem',
    'spacing-7': '1.5rem',
    'spacing-8': '2rem',
} as const;

Above are all the px values that are used consistently throughout each Figma component and layout for padding and gaps. (ofc use rem if that is how yall do it in the codebase)

See the Figma button component in Dev Mode to read my annotations and properties that I have highlighted for some variants: https://www.figma.com/design/8tsCay2FRqctrdcZ3r9Ahw/UT-Registration-Plus?node-id=1008-9767&m=dev

• Ignore the button states (hover, pressed, disabled) However, for the new variants (small/minimal) just use the same state properties as used in existing buttons.
• Add new variants
• Ensure spacing system is used for padding and gaps
• Ensure all other properties of each button variant in your PR is consistent with the button properties in the Figma

Note: You must be invited to the Figma with view permissions to see annotations in Dev Mode