[Bug] Unable to close change requests

[adamc-sp]

Issue Description

When attempting to close a change request, the screen initially went blank and upon refresh, the change request was not closed. As reported in terminusdb/terminusdb#2116

With the fix in #312, this instead brings up an error modal saying "Schema check failure undefined"

Issue explanation

The constant for closing a change request is supposed to be Close but is stored as Closed as per the change request api: https://github.com/terminusdb/terminusdb-change-request-api/blob/main/src/change_request_schema.json

This causes generally all handling to not work properly

[adamc-sp]

@GavinMendelGleason another small one