Moves all of the "source" and "tool" implementations into their own
packages. This layout makes it a bit more clear where the
implementations are, and seems likely to scale more cleanly as more
sources and tools are added.
1. Calculate tool manifests when server starts.
2. Add toolset manifest endpoints.
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Co-authored-by: Kurtis Van Gent <31518063+kurtisvg@users.noreply.github.com>
Add `Toolset` implementation to the `tools` package:
- struct and configs.
- Custom `UnmarshalYAML` function.
- Initialization function that validates if tools specified for the
toolset exist.
