Make monitoring Index tab sort Status by ascending/descending severity of Status

[adoerrES]

Describe the feature:
Kibana Monitoring sorting

Describe a specific use case for the feature:

In 7.4.1 a user expected that sorting indices by Status column on the Indices monitoring tab of Kibana would sort by status level e.g:

green (good),
yellow (worse),
red (worst)

...and vice versa. But it appears we sort the column alphabetically by color name (or some other way), so it is ordered:

yellow (worse),
red (worst),
green (good).

...and vice versa. Screenshot attached of the undesirable order.

The user expected the sort to be ordered by the ascending/descending severity of status, not by the order of the color names, as it makes it hard to organize which indices are in a questionable/bad state.

[elasticmachine]

Pinging @elastic/stack-monitoring (Team:Monitoring)

[igoristic]

Worth noting that column's .sortable property can also take methods (besides booleans), so it might look something like this:

field: 'status',
sortable: ({ status }) => ({ gray: 1, green: 2, yellow: 3, red: 4 }[status]),
render:...

I guess this would apply to all columns that use <StatusIcon> directly (or as a child)

[elasticmachine]

Pinging @elastic/infra-monitoring-ui (Team:Infra Monitoring UI)