Update the buttons to use the "new" variants and sizes

[obulat]

Description

After the button variants and sizes are updated to match the Figma styles, we need to update the code to use the new styles.

Components

• Sources page: "Add new source" button should be filled-pink-large Update sources button #1021
• CTA button should be filled-pink Update the CTA buttons #1049
• The "Report this content" should be filled-dark, and the buttons in the repost popover need to be updated Update report buttons #1004
• "Copy" button Update the Copy button #1140
• VSearchTypeButton Use bordered-white variant for VSearchTypeButton.vue #1146
• VBackToResults Update Back to results button to use the new VButton variant and size #1141