Feature: implement diff threshold boundary to fail builds

[Hotell]

originally posted in fluent core microsoft/fluentui#22404

Configurable from monosize config (global/local) and CLI

Not sure about the api, some mixture of following?

• https://github.com/siddharthkp/bundlesize
• https://webpack.js.org/configuration/performance/

[layershifter]

The idea was to have following points of configuration:

• (default) have some number
• monosize config: allow to configure threshold (diff)
• fixture config (default export): configure threshold or max size of a fixture