Fix no result style change

[maryam-saeidi]

Kibana version: v 8.4.0-SNAPSHOT

Bug description

When I load the observability alert page, if there is no alert, I see a No result message first without an image and then with the image, and as a result, it seems we are showing 2 different messages despite the fact that both of them are the same.
One possible fix is to have a placeholder for the image to not change the position of content after loading the image. (At the start, I thought we show 2 different no-result messages)

Screenshots

first	second

You can check the issue in this screen recording:

Screen-Recording-2022-08-09-at-12.44.46-PM.mp4

Acceptance criteria

• Fix the No result message style change due to loading the image with a delay

[elasticmachine]

Pinging @elastic/actionable-observability (Team: Actionable Observability)

[emma-raffenne]

@maryam-saeidi and @XavierM
This seems to be the "old" alert table. Would the same happen with the shareable one?

[maryam-saeidi]

@emma-raffenne Not sure if it happens in the new table as well or not. Since the No result message Is in the second tab, I cannot easily refresh the page and check the result. Maybe we can keep this bug on hold until we integrate the new alert table and check the result.

[maryam-saeidi]

Btw, I see another issue in the alert table on the rule details page:

The message says Try searching over a longer period... but there is no time filter. Does it make sense to use another message here?

[emma-raffenne]

@emma-raffenne Not sure if it happens in the new table as well or not. Since the No result message Is in the second tab, I cannot easily refresh the page and check the result. Maybe we can keep this bug on hold until we integrate the new alert table and check the result.

Makes sense to check once we have integrated the new one. Although, if the "no data" message was going to be changed, we need to take into account the context, i.e. if it's in the rule detail page, it would make no sense to propose to create a new rule for example.