[Label] Create a new label

[dab246]

Specs

• Add a tag section under the folder section
• When user click on ‘+’ button, we open a creation modal
  • User can enter the label name
    • If label already exists, we display an error : ‘A tag with this name already exists. Please choose a different name.’
  • User can select color
  • When user clicks on ‘Create’ button, we create this label and display it on the left menu