On my/certificate page:

• the button + Add entry should be overwritten with the Modal under the button Add another key and certificate pair
• the delete button for certificate should perform a custom function (delete also the key from local storage)
• add a green (red) tick in certificate table when the corresponding key is present (or not) in the local storage

This works can be done on to the branch feat/es256_certificate following what we did till now

For later: when there is a red tick for a certificate there should be a way to load also only the private key related to the certificate