Create empty file-group doesn't validate container name

[ascobie]

Attempting to create an empty file group/container doesn't validate the container name is valid and so attempting to save it crashes the application ....

Also can we change the button text from "Confirm" to "Save" or "Create".

It also need's to check for duplicate container names and length. This code is already in the FileGroupCreateFormComponent:

        name: ["", [
            Validators.required,
            Validators.maxLength(validation.maxLength.fileGroup),
            Validators.pattern(validation.regex.fileGroup),
        ], [
                this._validateFileGroupName.bind(this),
            ]],