Support Azure DevOps as a first-class codehost

[malomarrec]

There's also a product gap tracking this:
https://sourcegraph2020.lightning.force.com/lightning/r/Product_Gap__c/a1B5b00000LABF7EAP/view

Impacted customers

• https://github.com/sourcegraph/accounts/issues/8293

[malomarrec]

Possible duplicates of https://github.com/sourcegraph/sourcegraph/issues/23828, although the scope there is not clear to me.
This was briefly discussed here:
sourcegraph/handbook#2381

There's interesting chatter over whether it's gonna be EOL. ADO Server is EOL in 2024, but what about cloud? https://www.reddit.com/r/azuredevops/comments/eupvn1/is_microsoft_abandoning_azure_devops/

[github-actions]

Heads up @caugustus-sourcegraph @kevinwojo @michaellzc - the "team/delivery" label was applied to this issue.

[jplahn]

I think this should be tagged against Repo Management.

[github-actions]

Heads up @jplahn - the "team/repo-management" label was applied to this issue.

[malomarrec]

My bad :/

[eseliger]

Azure DevOps is supported in Sourcegraph today: https://docs.sourcegraph.com/admin/external_service/azuredevops!