Allow standalone field components without forms

[aptkingston]

Description

This PR allows using field components without forms. That means they do not need to be wrapped in a Form component (but still can be, of course) and provide a global binding of their value to use as you like.

Almost all field types support this usage. The only exceptions are attachments (both single and multiple), signatures and relationship pickers, as these require being bound to a datasource to be functional.

Clarification:

• The field setting is now optional when using fields standalone. The component name rather than the field setting will be used to generate the global binding
• All settings work as expected - validation, default values, on change etc.

Quick example of filtering using a standalone field

Here's a screen with a table, and I've dropped an options picker above it:

Here's my component tree - just the table and some fields without a form:

I can filter my table using the new global bindings:

The field configuration can be left completely blank (I've added a placeholder but that's optional of course):

Quick example of saving rows

You also don't need a form to create rows when using fields like this. You can simply add a button, leave datasource to "None" and bind up the values:

Launchcontrol

Allow using fields without forms.

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