feat: Allow excluding default plugins

[maxpatiiuk]

Custom Element Manifest Analyzer comes with over 20 plugins built-in.
Quite a few of them relate to extracting information about variables, arrow functions, function declarations and even mixins.

In our codebase, we have many components, so keeping build fast is nice. We don't want to expose any variables/functions/mixins in the documentation, so generating manifest for those is a waste.
We also don't need the default blocklist plugins as we have a custom plugin for deciding what gets included

Would it be possible for CEM to add a way to exclude default plugins (in the javascript API)?

Possible implementations:

• Add a prop like transformConfig: (config:CemConfig)=>CemConfig that will act similar to Vite's configResolved(), letting us manipulate the final resolved config.
• Add a prop like includePlugin: (pluginName:string)=>boolean for selecting what plugins should be included
• Add a prop like includeDefaultPlugins: boolean for excluding all default plugins (at which point they will have to be explicitly provided to the plugins array)