[bug] Web executor fill action behavior change between 1.1.0 and 1.2.0

[ArnaudLec]

We are currently validating the impacts for migrating Venom to v1.2.0 and found a regression on the web executor when filling inputs which already contained values.

Before, with the v1.1.0, when filling a field which already contained a value, it was clearing the value before filling the input.

Now it concatenates the value and there's no option to clear the input beforehand.

Our use case is an option to duplicate a configuration in a screen and the form comes back already filled.