New slack integration is unpolished - Actions need to be faster + Triaged messaged should shrink more

### Problem Statement

Heyas,

Just want to drop some feedback re the new slack integration. It adds some nice bits, but also leaves a lot to be desired compared to the previous offering.

- The neat status strip along the left has been replaced with a crude red/white emoji dot. The sentry icon itself also seems to change colour between pink and purple sometimes as well; why?? Can we bring back the status strip?
- Presentation of builtin data is neater, but custom fields are now really clunky. Do we need to wrap absolutely everything in code tags?
- The slack message doesn't shrink down nearly as much anymore when it gets assigned/resolved. Could cut out even more info from it in these cases. This makes it hard to differentiate between items that are addressed and those that still need to be looked at.
- Selection of actions or assignees is now so much slower as it seems it needs to hit sentry's api on the fly, as opposed to having the choices preloaded into the dropdown. This is really annoying!

Hopefully the integration is still a work in progress, and there'll be a little more time spent to polish this off..

Cheers,

### Solution Brainstorm

1) Bring back the status strip, so that the sentry integration uses the same familiar interface that other integrations use.
2) Make custom fields a smidge smaller, bold the label, remove the code tags from the value.
3) Add an option to configure what builtin data is shared. "Suspect commit" isn't hyperlinked so it's not hugely useful; Project/Alert/Short ID may be handy for some multi-project setups, but to many companies this will just be noise.
4) Once an issue is assigned/resolved, strip back the majority of the data, as it's no longer needed. Probs just hyperlinked title and the who was assigned/who resolved is sufficient.
5) Review the action options so that additional api calls don't need to be made to sentry to determine dropdown options.

### Product Area

Settings - Integrations