index patterns scripted fields script type functionality needs removal

[mattkime]

The index patterns scripted fields list has functionality to display the script type and to filter by script type. As of 7.0, there are only painless scripts. The code still needs to be cleaned up. I discovered the code via test/functional/apps/management/_scripted_fields_filter.js

[elasticmachine]

Pinging @elastic/kibana-app (Team:KibanaApp)

[elasticmachine]

Pinging @elastic/kibana-app-arch (Team:AppArch)

[rashmivkulkarni]

In the dropdown- there is painless and expression language. I do see it on master. Was able to pull down expression and create a script.

[lukeelmers]

@rashmivkulkarni I am not sure if the linked PR resolved this issue; IIRC, this issue exists to track the removal of the expression-based scripted fields.

(This is a breaking change that we intend to make in 8.0)

[lukeelmers]

Although looking at this issue again, I think it might be a duplicate of #77669 so maybe it's okay to close anyway. WDYT @mattkime ?