Allows use of externally owned transactions for writes

[jimmyp]

Nevermore already had the concept of accepting an external transaction to use for reads. This PR extends that behaviour to writes.

Commit() was renamed to TryCommit() to convey that it can now throw an exception if the externally provided transaction has already been committed elsewhere. This caused a lot of noise in the tests but I think the rename is valuable otherwise this would be a breaking change.

[sc-71481]

[michaelongso]

Tagged Cloud PT, https://octopusdeploy.slack.com/archives/C01Q95KPRM4/p1709254205324879

No impact for Cloud PT as they have removed Nevermore from Cloud Portal

[gb-8]

Commit() was renamed to TryCommit() to convey that it can now throw an exception if the externally provided transaction has already been committed elsewhere.

I'm not following this. Previously Commit() would throw an exception if the SQL transaction was externally owned. Now it just silently does nothing. That is a breaking change.

The new TryCommit() will throw for externally owned SQL transactions, like the old Commit() method - it won't even get as far as finding out if the externally owned SQL transaction has already been committed.

I'm confused.

[jimmyp]

Previously Commit() would throw an exception if the SQL transaction was externally owned.

You are totally right, I got myself confused while trying to use the MS convention on TryXXX methods... To not make this a breaking change I'll have to not use this convention

[shortcut-integration]

This pull request has been linked to Shortcut Story #71481: Get agreement with PET regarding shared transaction between NSB and Nevermore.

[adam-mccoy]

Blocking this one for further discussion.

[adam-mccoy]

Per the feedback on https://github.com/OctopusDeploy/OctopusDeploy/pull/23120, we'd rather not introduce a different way to commit a Nevermore transaction. Rather, the consumer (Octopus Server) should be aware of whether the SQL transaction is externally owned and simply not call Commit() on the Nevermore transaction in that case. Happy to assist with ways to solve that.