Editing a scripted field causes errors

[lukasolson]

Steps to reproduce:

1. Create a new scripted field (I just kept the defaults and named it "foo" and used "1" as the script)
2. Save the scripted field
3. Edit the scripted field (don't need to even change anything)
4. Save the scripted field again
5. Attempt to edit the scripted field again

You'll get a blank page and the following error in the console:

TypeError: field.format.params is not a function
    at FieldEditorComponent._callee$ (field_editor.js:153)
    at tryCatch (runtime.js:62)
    at Generator.invoke [as _invoke] (runtime.js:288)
    at Generator.prototype.(anonymous function) [as next] (webpack://%5Bname%5D/./node_modules/regenerator-runtime/runtime.js?:114:21)
    at step (field_editor.js:79)
    at eval (field_editor.js:79)

If you try to go to Discover with that index pattern selected, you'll get this error:

angular.js:14800 TypeError: field.format.getConverterFor is not a function
    at convert (_format_hit.js:38)
    at eval (_format_hit.js:57)
    at eval (index.js:3117)
    at baseForOwn (index.js:2090)
    at Function.eval [as forOwn] (index.js:3422)
    at IndexPattern.formatHit (_format_hit.js:55)
    at SourceFormat.sourceToHtml (source.js:53)
    at recurse (content_types.js:32)
    at eval (content_types.js:46)
    at convert (_format_hit.js:38)

Looks like the field formatter is not being saved the second time around, not sure exactly why.

[elasticmachine]

Pinging @elastic/kibana-app

[lukasolson]

Ironically, refreshing the page seems to fix the error.

[lizozom]

fixed by #34679