chore: Add buffer as a chart dependency (#1899)

This adds an explicit dependency to `buffer` to `@deephaven/chart` which
we currently get implicitly from `browserify` in `golden-layout`.
`plotly.js` depends on `typedarray-pool` which depends on `buffer`, but
doesn't list it.

I opened a PR with `typedarray-pool`, but doesn't seem it's an active
repo any more. mikolalysenko/typedarray-pool#11

The docs uses webpack 5 w/ docusaurus and I added `buffer` when adding
chart support, so this should be all that's needed.
deephaven/deephaven.io@6a8bcf2#diff-7ae45ad102eab3b6d7e7896acd08c427a9b25b346470d7bc6507b6481575d519

Author: mattrunyon

package-lock.json

@@ -34,6 +34,7 @@
     "@deephaven/log": "file:../log",
     "@deephaven/react-hooks": "file:../react-hooks",
     "@deephaven/utils": "file:../utils",
+    "buffer": "^6.0.3",
     "deep-equal": "^2.0.5",
     "lodash.debounce": "^4.0.8",
     "lodash.set": "^4.3.2",