test: ensure reasoning tokens are sent

[ammario]

For at least Anthropic models, we can send past reasoning traces and expect the new response to consider them. Need to think of a sendMessage.ts.test that can ensure a new sendMessage on an existing workspace is able to compute answers from those traces.

[ibetitsmike]

Make sure to check which models actually support the reasoning traces and whether the inclusion is happening for supported models and we have tests for it.