Makes it easier to test and know for certain where the value is being
set from. Previously it wasn't clear how the write to directory was
being modified or read in the global config object.
Name it consistently, Context can be a bit ambiguous. Also define the
tags used to pass data from the platform layer to the component layer as
go constants in the core api for clear documentation.
There are only two version specific cue builders, a Platform and a
component BuildPlan. The platform is anemic while the component holds
most of the behavior of the Holos rendering pipeline. Without this
patch the two types of builders were mixed together in the same package.
This patch refactors the version specific builders into the platform and
component packages respectively. The version specific BuildPlan builder
is where most of the behavior lies and what we expect to evolve most
over time. With the typemeta.yaml approach, we can easily switch code
paths, isolated to the process boundary since holos render platform
invokes sub processes for each holos render component command.
This patch helps focus on good test coverage by establishing a clear
area to add version specific test cases, both for the platform layer and
the individual component layer.
