[Obs][Alerts] Control "group by" view via the URL

[simianhacker]

Right now when we are generating links to Alerts from ECO we'd like to control the "group by" view via the URL. Right now when you change to the "group by" view it appears that it only changes the state of the page and not the URL state.

AC

• Control which group by field is used to group the alerts (Rule Name, Source, Custom Field)
• Control which grouping are expanded – The primary use case for ECO is to link to the alerts page, grouped by Rule Name, and expand the rule name base on rule.id).

[elasticmachine]

Pinging @elastic/obs-ux-management-team (Team:obs-ux-management)

[jasonrhodes]

NOTE: tying the group by selection to the URL state should be straightforward, so we should make sure we do that in this issue. Let's make sure we understand how this works with nested group by.

The second point, controlling which group by is open/closed, might need a little more thinking so if we need to split that out to a new issue, that's ok.

[maryam-saeidi]

Created a separate ticket for the second point: #197775