add flag to support debug inclusion within a running project

[JScearcy]

Summary

Add flags in a couple places to define DEBUG during the esbuild bundle process. This opens up the ability to conditionally include instrumentation in the *.js output.

This opens up the ability to add things like this:

DEBUG && performance.mark(..)

Following this doc: https://esbuild.github.io/api/#define

This is part of pre-work for a set of features to test performance and functionality

[hayleigh-dot-dev]

Dropping a comment here so it doesn't look like it's being ignored. We're gonna leave this open until we have a clearer idea of what debugging/benchmarking in Lustre itself might look like.

[JScearcy]

Closing - I think there are better options here :D