Enable the ability to log the payloads on the server side

In the PowerShell extension, we ask users to upload the logs that all come from a central folder. This includes:

• client logs (vscode-powershell)
• startup logs before the language server is up
• language server logs (PowerShell Editor Services)

This includes everything including payloads. We also have 1 setting that handles what is included in the logs:

powerShell.developer.logLevel

That maps to a log level in the server.

Since csharp-lsp doesn't give us the ability to log the payload server side, we will have to adapt to a more complicated logging story... relying on the user to use both powerShell.developer.logLevel and powershell.trace.server in order to get verbose logs from the vscode client side.

Also, we will have to tell the user to copy language server logs from the output window, and attach the other logs from the file system. It's messy.

If csharp-lsp exposed a way to include payloads in logging, then we would be able to keep our simple system that folks already know.

Start by reviewing the csharp-lsp server-side logging behavior described in the issue and how payloads are currently excluded. Compare it with the PowerShell extension's powerShell.developer.logLevel and powershell.trace.server settings; done means a documented way for server logs to include payloads without requiring separate client and output-window logs.