Mappings new source field #maxlength value

The feeds_ex module extends the BlankSource of Feeds module here:
feeds_ex/src/Feeds/CustomSource/JsonSource.php

When inspecting the BlankSource in Feeds module, we can see that there is no #maxlength associated: feeds/src/Feeds/CustomSource/BlankSource.php

So, the limit of the 128 chars length is imposed by Core's config entity.
Here is a discussion about it and where to go in the future #3331028 ✨ Increase or remove default textfield #maxlength=128 Active

To circumvent this limitation, we can just add the maxlength to the BlankSource, and all the modules/source that extends it, will benefit from the change, like this one:

class JsonSource extends BlankSource {

So, here is a patch to force the #maxlength of BlankSource to be 1024.

The patch in #7 failed to apply, but I applied the changes from it manually and committed that. Thanks!

Automatically closed - issue fixed for 2 weeks with no activity.