Allow `web.pre_compress` with gzip too.

## Feature Request

Today, dioxus has `web.pre_compress` option which will generate brotli files. But brotli is only enabled for sites using `https`, [not plain `http`](https://stackoverflow.com/questions/43862412/why-is-brotli-not-supported-on-http).

## Implement Suggestion

`web.pre_compress = false` and `web.pre_compress = true` will remain as they are, but users will be able to have ``web.pre_compress = "gzip"` and `web.pre_compress = "brotli"` too.