Handle keepNames esbuild option

[doowb]

Since esbuild options are not directly exposed, I'd like to propose either setting the keepNames esbuild option to true or exposing a similar option in remix.config.js.

By exposing an option, remix will still be able to change the underlying build system without exposing esbuild options directly.

The reasoning for this option is to ensure that the dependencies in serverDependenciesToBundle that make use of function and class names will continue to work. I ran into an issue when bundling oidc-provider because class names were removed, causing the library to pass empty strings in places where it expects the class name.

In the mean time, I'm using a work-around similar to the one in this comment