Split up HloExecutionProfile into a set of re-usable components

The end goal is to have Hlo profiling support in XlaJitCompiledCpuFunction and
eventually AOT compiled XlaCompiledCpuFunction.

This change leaves the HloExecutionProfile interface mostly intact -- internally
it uses the new split out components to do what it did before.  However, in
future CLs:

 - I'll extract out a HloExecutionProfilePrototype that contains the
   HloProfilePrinter, the OwningHloProfilePrinterStaticData and the
   HloToProfileIndex.  This will then live in the Executable (if profiling is
   enabled).

 - The HloExecutionProfile for a specific execution will have a pointer to the
   parent HloExecutionProfilePrototype, which it will use to paginate
   profile_counters_.

 - The CPU backend will use the HloToProfileIndex in the
   HloExecutionProfilePrototype to map hlo instructions to profile counter
   offsets.  This will make the indices in the generated code "line up" with the
   indices that the HloProfilePrinter expects.

These changes will allow the XlaJitCompiledCpuFunction (and later AOT) clients
to pass in an appropriately sized zeroed buffer to the generated function and
then pass that same buffer to the appropriate HloProfilePrinter to get a
textual Hlo profile.

PiperOrigin-RevId: 175613737