Telemetry update

[CalebCourier]

Changes

• Migrate from Credentials class to RC class; make this a config type class that is 1:1 with the .guardrailsrc file
• Track RC config on user settings; this gives us one place to fetch the config instead of re-reading from the file every time and allows the user to set config values programmatically.
• Add span attribute to distinguish structured data output from unstructured
• Use span contexts for time spans
  • Make tracing methods generic so we don't alter the return types
  • The above didn't work because the type checkers don't allow a TypeVar (generic) to represent a different TypeVar if the latter is bound to other types. The solution instead was to just remove typing from the trace methods' signature so they do not override the original methods annotations.

[notion-workspace]

Telemetry Updates

[AlejandroEsquivel]

@zsimjee