Resolve "Configuration Editor Validation"

Closes #9

See merge request t3o/election!4

Allow an admin user, to edit the election config, if the config is
misconfigured.

Require TYPO3 Version 9

KUDOS Nicole Cordes

Kudos to Nicole Cordes and Helmut Hummel

Resolve "Show Nominees at active elections"

Closes #3

See merge request t3o/election!2

Resolve "TYPO3 8.7 compatibility"

Closes #1

See merge request t3o/election!1