[grouping info] Description of rule used doesn't always match rule

In the Grouping Info section of the issue details page, we tell you what rule caused us to make a given stacktrace modification, which is helpful in theory, but can be confusing, because we don't actually show you the actual rule, but a modified description thereof. For example, this explanation in the UI


came from this rule in the user's project settings


We should quote the rule itself. (Relevant code is [here](https://github.com/getsentry/sentry/blob/69d4de691f721930b80ab96be5e3a21b01e967d9/src/sentry/grouping/enhancer/actions.py#L119-L129).)

(Note that this isn't always a problem. The descriptions from from this correspondence, and in many cases they do match:

https://github.com/getsentry/sentry/blob/69d4de691f721930b80ab96be5e3a21b01e967d9/src/sentry/grouping/enhancer/matchers.py#L49-L70

But in cases where they don't, it'd be clearer to both the users and us if we were to use the actual text of the rule.)