ISBAT configure the Form block field attributes

My form is submits to a 3rd-party endpoint (via Ajax).
I want to be free to configure (or at least override) the **name** attribute of the fields.
- `` _instead of_
``

- `Subscribe` _instead of_
`Subscribe`

**Describe the solution you'd like**
- Individual per-field filters having (`$form` and `$field`) as arguments and returning the modified `$field` array. (`$field` would contain attribute, content and (default) values (list) for select/checkboxes, ...)
- Per-field final markup filter
- It's hard offer good but still simple form override abilities (wrt both attributes & data but also layout). An nice solution would be to introduce some Twig (via [Timber](https://github.com/timber/timber)) template/attributes override & inheritance system.

**Describe alternatives you've considered**
I moved away from GravityForms because it makes simple form tweaking terribly complex, the markup output is quite opinionated and convenience hooks are not provided where they would be useful.