Add support for loading webassembly plugins (Server)

[Astn]

Two implementations I found are by @migueldeicaza and one by @bytecodealliance.

https://github.com/migueldeicaza/WasmerSharp https://bytecodealliance.github.io/wasmtime/lang-dotnet.html

Objectives

• [ ] Define metadata / schema for how we look for plugins
• [ ] Define which locations in the stack a plugin can be hooked in
• [ ] Load plugins that are enabled
• [ ] Use the plugins
• [ ] Add metrics support for tracking plugin health
• [ ] Disable plugins that a behaving badly

[Astn]

Some locations in the stack we could use plugins

• saving and loading DataBlocks
  • We might want to do some text processing
  • Compression
  • Rewriting text formatted number to a native representation
• Indexing Providers
  • Could enable indexing of spacial data
  • Could enable full-text indexing
• Query Operators
  • Someone wants to add a custom operator to be available to one of the languages we support
• A way to load map/reduce jobs
• Import provider
• Export provider