[Rule] Implement big dependencies rule

[iranreyes]

Idea

Create a rule that checks the file size of npm dependencies and alerts if there are dependencies with a bigger size than the one specified in the adviser configuration file.

Rule Specifications

Name: package-size
Arguments: threshold, whitelist

Implementation

1. Find how to calculate package-sizes (for the browser) in the best way (performance and accurately)
2. Implement it on the rule

package-size

1. Try to find an npm package that does it
2. If doesn't exist, review how bundlephobia, import-cost, bundlesize are doing it
3. If it's hard to reproduce it, use one of the previous ones (bundlephobia API - https://bundlephobia.com/api/size?package=adviser)

Notes

Create documentation for the rule within /docs/rules
Add metadata to the rule
Update the Plugin general README and add the new rule

[iranreyes]

@colinmaclachlan There are security vulnerabilities with the dependencies of this rule