feat(accessibility): set focus on the first invalid form field

[SGrueber]

PR Type

[ ] Bugfix
[x] Feature
[ ] Code style update (formatting, local variables)
[x] Refactoring (no functional changes, no API changes)
[ ] Build-related changes
[ ] CI-related changes
[ ] Documentation content changes
[ ] Application / infrastructure changes
[ ] Other:

What Is the Current Behavior?

1. On form submit the invalid form fields are highlighted in case of validation errors, but the focus remains unchanged.
2. In many form components the method 'markAsDirtyRecursive' is used to mark all form fields as dirty after form submit to secure the untouched required form fields are shown as invalid. This is not necessary for formly forms. In these components there is often a variable (e.g. submitDisabled etc.) used to determine whether the user has already submitted the form in order to disable the submit button after form submit if the form is invalid. This variable is also unnecessary.

Issue Number: Closes #

What Is the New Behavior?

1. The accessibility has been improved regarding the following guideline: (WCAG 3.3.1 - Error Identification)
   A directive 'ishFormSubmit' has been introduced for form html elements to set the focus automatically on the first invalid form field after form submit.
2. The form components have been refactored. After form submit the 'markAsDirtyRecursive' method is not called any more for formly forms. The button is disabled by using the property 'submitted' from a corresponding FormGroupDirective defining a variable #form="ngForm" at the form html element.

Does this PR Introduce a Breaking Change?

[ ] Yes
[x] No

Other Information

AB#103801