This repo has been placing using directives within namespace blocks. The apparent benefit was occasional brevity for "nearby" namespaces: within the Fixie.Tests namespace, you could simply say using Assertions to bring in the nearby namespace Fixie.Tests.Assertions. This was the only benefit, and switching to it was a Pyrrhic victory for two reasons:

1. It does not play nicely with the more modern "global using" feature (explicit or implicit), forcing redundant directives and therefore less brevity.
2. Switching away from this meager brevity unskillfully is risky as the meaning of some type name in a code file might silently change if you merely relocate the namespace directive below existing using directives. Fortunately most such conflicts would coincidentally surface as a compiler error based on usages of the identifier, but still: here be dragons.

This reorders using vs namespace as a step towards cleanly applying implicit/global using directives in a subsequent PR. By applying this code change separately from the implicit/global using directives, each can be more easily reviewed in isolation.

This was done manually. For each visited file, already-abbreviated using directives were first expanded to their fully-qualified equivalent, letting the IDE first confirm what the implied full name was. Once all using directives in a code file were fully-qualified, they could be safely cut and pasted before the namespace with confidence that the move could not alter the meaning of the following code.

Two name conflicts were encountered and resolved:

1. Console tends to be ambiguous in the tests when we can alternately mean System.Console or Fixie.Console. We resolve this by always referring to System.Console... explicitly in the tests, and can mean Fixie.Console implicitly otherwise.

2. TestResult can mean either Microsoft.VisualStudio.TestPlatform.ObjectModel.TestResult or Fixie.TestResult. We resolve this in both VsExecutionRecorder and VsExecutionRecorderTests by including the following alias after the namespace declaration:

   using TestResult = Microsoft.VisualStudio.TestPlatform.ObjectModel.TestResult;