Add automatic handling of "ElementNotInteractable" exceptions

In the WebDriver protocol, when a command fails because it can not
interact with the target element, an "element not interactable" error is
generated. It can be a transitive issue (for example, due to an
animation), so when the error is received the command should be tried
again, just like done, for example, with "ElementNotVisible" exceptions.

However, the last version of the "instaclick/php-webdriver" library
compatible with the Selenium Driver of Mink did not support yet that
WebDriver error. And even if Chrome is run using the old protocol an
unknown "element not interactable" error can be received anyway in some
cases. When an unknown error is received by the
"instaclick/php-webdriver" library it is thrown as a generic Exception
so, until the library can be updated, the message of generic exceptions
is checked and the command is retried if it matched.

For the time being "element not interactable" errors are handled like
"ElementNotVisible" exceptions; this may need to change once the error
is better understood.

Signed-off-by: Daniel Calviño Sánchez <danxuliu@gmail.com>