dillon1000/react

[DevTools] Unify by using ReactFunctionLocation type instead of Source (#33955)

In RSC and other stacks now we use a lot of `ReactFunctionLocation` type
to represent the location of a function. I.e. the location of the
beginning of the function (the enclosing line/col) that is represented
by the "Source" of the function. This is also what the parent Component
Stacks represents.

As opposed to `ReactCallSite` which is what normal stack traces and
owner stacks represent. I.e. the line/column number of the callsite into
the next function.

We can start sharing more code by using the `ReactFunctionLocation` type
to represent the component source location and it also helps clarify
which ones are function locations and which ones are callsites as we
start adding more stack traces (e.g. for async debug info and owner
stack traces).