[WIP] [Form] Fixed TimeType: inconsistent behavior between input as "array" and as "string" in form data

If you use the TimeType with option "input => array" and provide hour + minute then the model data is an array with 2 values (of course hour + minute)
But if you change the option "input" to "string" the model data is something like this: "02:02:02" but it should be "02:02"

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | yes (?)
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

TODO

- [ ] provide compatibility layer to support the old behavior