Merge branch 'hotfix/#6854-autocomplete-as-valid-textarea-and-select-attribute'

Close #6854
Allow Session\Container names to start with numbers

Useful for names generated or prefixed with hashes or checksums.
Also adds another backslash for better readability.
Update ContainerTest.php

Fixed test
Update ContainerTest.php

Test added
Merge branch 'hotfix/#6858-allow-zend-session-container-name-with-numeric-name-initial' into develop

Close #6858
Forward port #6858