Add Folder Color support

[keeferrourke]

Some other popular themes support changing the default folder colours using a Nautilus/Caja/Nemo extension called "Folder Color". Support should be added to La Capitaine, following these guidelines

Aim to complete sections 1, 2, and 3 outlined in the above guidelines:

• [x] Add folder_color_[blue | brown | green | grey | orange | pink | purple | red | yellow] SVGs
• [ ] Add desktop, downloads, documents, pictures, public, templates, and videos colour varients
• [ ] Add folder_emblem_[favorite | finished | important | in_progress] SVGs
• [ ] Add actions/22x22/folder_color_picker.svg
• [ ] Add actions/22x22/folder_color_edit.svg
• [ ] Add actions/22x22/folder_color_undo.svg

[keeferrourke]

Moving this to 0.7.0 release. It's been too long since 0.5.0.

[s1-ranjan]

Required two different colour folders namely: Violet,Pink because Magenta is linked to Pink and Purple is linked to Violet, Please have a look in the following image: