Preserve symbol names in the web version of PHP for easier debugging

[adamziel]

What is this PR doing?

Related to #1152

Preserves the symbol names in web PHP builds to enable debugging based on the reports collected by the error reporting modal.

Unfortunately, it increases the light bundle size by 250-400kb and the kitchen sink bundle size by ~700kb.

Open questions

• Would it be possible to produce a separate DWARF file instead and use it to decipher the minified stack traces? Could it work as a web app? Or could the error collector endpoint apply that transform? It would be an extra step and could require additional tooling, so we might need to merge this one first and tackle that as a follow-up issue.

Testing instructions

Just confirm the tests are green.