Improve style and icons

[daudix]

Some minor style changes to make the extension look more in place with GNOME

• Replace clipboard content icons with the GNOME ones
• Improve indicator icons
• Improve incognito mode icon
• Create new placeholder images to be in GNOME style (at least I tried)
• Change some colors
• Change content font to Cantarell
• Change text font to Monospace
• Fix icons not being recolored by adding -symbolic in the file name

[oae]

I have made all items customizable through the settings. Can you pull the latest version?

[daudix]

Yup, working on it rn

[daudix]

I think it should be fine now

[oae]

This looks really good. Thank you very much.

[daudix]

I'm glad you liked it :D