[DESIGN] Rethink the Close/Removal flow for batch change

Created by: danielmarquespt

The flow to remove draft batch changes from the list is too complex without proper guidance. This needs to be easier as its a useful and standard feature of any list

The flow right now:

Related Threads: https://sourcegraph.slack.com/archives/CMMTWQQ49/p1657673534806369 https://sourcegraph.slack.com/archives/C03CSAER9LK/p1658783480438529

Proposed solutions

While some executions are actual draft (I want to get back to it later), some are not valuable to persist (I played with it, and don't need it anymore). It'd probably make sense to have a discard button easily accessible from the batch change execution page, and maybe from the batch changes list.

Design Pending