119/button styling

[nichgalzin]

Description

Closes #119

This pull request includes several updates to the BackButton, PopupCard, and global button styles, along with a minor change to the FavouritesPage component. The most important changes are summarised below:

Updates to BackButton component:

• Increased the size of the back button in BackButton.css to improve visibility.
• Removed unnecessary text-xl class from the back button in BackButton.tsx to simplify the styling.

Updates to PopupCard component:

• Added a new close-button--container class and adjusted the popup-card--remove-button class in PopupCard.css to enhance the styling and positioning of the remove button.
• Updated the PopupCard.tsx to include a new close button container and refactored the remove button handling for better user interaction.

Global button styles:

• Modified global button styles in globals.css to reset border, background, and text alignment properties, and added focus styles for better accessibility.

Minor changes:

• Adjusted the FavouritesPage.tsx to move the key prop to the correct element for better React key management.
• Updated button styles in PopupInfo.css to align with global button styles and ensure consistency.

UI changes

[camelPhonso]

It's looking sharp but we've got some unintended changes going on need a bit of a fix for the z-index in the new buttons

[camelPhonso]

Smashing!