[FEATURE] Add extended YamlPersistenceManager

This YamlPersistenceManager first loads forms from Packages/*/*/Data/Forms/.
The first form found in a package will be used for rendering. If no form is
found the global TYPO3.Form.yamlPersistenceManager.savePath setting will
be used.

New forms are always created in the savePath, and changes to a form in a
package will also be saved in the global path to prevent changes to the
form in the original package.
[TASK] Add depedency to TYPO3.Neos.NodeTypes

This dependency is needed for overriding the default
TYPO3.Neos.NodeTypes:Form node type.
[TASK] Add custom template for the form node type

This custom template can be used by including it in TypoScript
and it will hide any output in te frontend if no formIdentifier
is selected.