Add loading icon to summary panel

[sinhaviraj]

I have added a loading icon to the summary section which used to load the contents without any visual indication to the user. Now while the initial summary is loading the loading icon would be visible to the user.

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[bwieger-atlassian-com]

Could you help us with a Loom video showing the user experience (not the code)?

And can you share the customer voice on this problem? Is there any quotes or data or industry best practices we can justify this change on?

[decompil3d]

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[bwieger-atlassian-com]

See comment above

[decompil3d]

@atlassian-cla-bot check

[sinhaviraj]

Could you help us with a Loom video showing the user experience (not the code)?

And can you share the customer voice on this problem? Is there any quotes or data or industry best practices we can justify this change on?

@bwieger-atlassian-com Here is the loom video https://www.loom.com/share/861a72679327419087cfaafc6972387f

I don't have a customer problem. I saw this as an opportunity for my first PR to improve the loading experience of summary section while viewing PR details. All other sections did have loading icons whereas for summary it used to load suddenly without any feedback to the user. This is why I felt maybe we should get this going.

[bwieger-atlassian-com]

@sinhaviraj The customer problem can be your own voice as well. Or a reference to an industry best practice.

Example:

As a user who clicks on a button with a long load time, I would like to see a visual indicator that my click is registered and something is happening.

The button for checking out a source branch on a PR takes a long time to load. So adding a loading state here so our customers are not confused.

[bwieger-atlassian-com]

LGTM!

Tested: https://www.loom.com/share/2957ba48c2354cc891bf7126d639b938?sid=1ae54646-2fd2-4dad-b04f-b3e6eb0d6026