Show number of successful repos instead of completed repos in variant analysis results view header

[robertbrignull]

Closes #2239

This PR aims to address the bug spotted in the issue linked above. We were showing the number of completed analyses instead of the number of successful analyses, and this caused confusion when actually looking through the results. This isn't how our original designs were so I think this is a bug and we didn't implement our designs correctly.

I try to generally improve this area by surfacing as many useful states as we can, and adding labels to the icons to explain what they mean. I also rewrite the text that previously said "Succeeded warnings" with something more descriptive and grammatically correct.

To see it in action try running some variant analyses, and to see all the possible states check out the storybook.

Checklist

• CHANGELOG.md has been updated to incorporate all user visible changes made by this pull request.
• Issues have been created for any UI or other user-facing changes made by this pull request.
• [Maintainers only] If this pull request makes user-facing changes that require documentation changes, open a corresponding docs pull request in the github/codeql repo and add the ready-for-doc-review label there.

[robertbrignull]

For those who can't run the code to try this out, I'll try to summarise the various states we can have.

The more "important" states takes precedent too, so if some repos were skipped but also analyses failed, then we'll show the red status and the more important tooltip message.

---

A fully successful analysis

• Repositories count shows 5/5 with a green status (tooltip is "Completed")
• Status text in 4th column says "Succeeded"

---

Where some analyses succeed but some fail

• Repositories count shows 98/100 with a red status (tooltip is "Some analyses failed")
  • Left side now only shows successful repositories
• Status text in 4th column says "Some analyses failed"

---

Where analysis is canceled

• Repositories count shows 5/10 with a red status (tooltip is "Some analyses were stopped")
  • Left side now only shows successful repositories
• Status text in 4th column says "Stopped"

---

Where some repositories are skipped

• Repositories count shows 4/4 with a yellow status (tooltip is "Some repositories were skipped")
  • Skipped repositories don't appear in this count, so we analysed 100% of the repos we could
  • The yellow status is just there to prompt you to look at the "No access" or "No database" tabs
• Status text in 4th column says "Succeeded"

[elenatanasoiu]

Looks good, had one small suggestion for readability, but it's not blocking.