Improve checkbox for screenreaders 2

[arturi]

This is a new PR from the same branch #2930, restored after Artur merged Merlijn’s PR too soon

We noticed, when navigating via keyboard and using a screen reader, the screen reader does not tell the user when they have checked one of the boxes next to a file or folder. It will tell them the state of the checkbox when it first gains focus, but pressing enter or the spacebar to check or uncheck the box does not result in any screen reader feedback.

• Improves checkboxes for screenreaders by using an actual input element with the right attributes.
• Fix eslint warnings

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Before

• Focus on checkbox of folder: "Select all files from folder This is shared, selected (1 of 2)"
  • Clicked: Nothing happens. When re-focussing: "Unselect all files from folder This is shared, selected (1 of 2)"
• Focus on folder: "Open folder This is shared, button"
• Focus on checkbox of file: "Select file some file name.docx, some file.docx , selected (2 of 2)". Notice the double file name.
  • Clicked: Nothing happens. When re-focussing: "Unselect file some file name.docx, some file.docx , selected (2 of 2)"

After

• Focus on checkbox of folder: "unticked, all files from folder This is Shared, checkbox (1 of 2)". No need for select/unselect.
  • Clicked: "ticked, all files from folder This is Shared, checkbox (1 of 2)"
• Focus on folder: "Open folder This is shared, button (1 of 2)"
• Focus on checkbox of file: "unticked, some file name.docx, checkbox (2 of 2)"
  • Clicked: "ticked, some file name.docx, checkbox (2 of 2)"