minifier: mangle properties

[sapphi-red]

Property names may take up the large part of the output size. Other minifiers have the mangle properties feature for those cases.

• esbuild: https://esbuild.github.io/api/#mangle-props
• SWC: https://swc.rs/docs/configuration/minification#jscminifymangleproperties
• terser: https://terser.org/docs/options/#mangle-properties-options
• uglifyjs: https://github.com/mishoo/UglifyJS/blob/master/README.md#cli-mangling-property-names---mangle-props

(I'm creating this issue as a placeholder, if you actually need this feature, make sure to add "👍" and describe the usecase in the comments)

[logaretm]

I'm doing an attempt at migrating to rolldown in Sentry's JavaScript repo, it would be great if we can have fine grained properties mangling. We have been using properties.regex and properties.reserved options to prevent specific properties from getting mangled.

We also use the top-level mangle.reserved but I don't think we need it. None of that should be needed actually, but just from the POV of matching the output with the rollup setup.