Remove lodash.pick from @useoptic/rulesets-base usage due to security issues and deprecations

[azen1k5]

Describe the bug
@useoptic/rulesets-base is using lodash.pick in version 4.4.0 which has a known security vulnerability. The lodash.pick package is also deprecated so there is no way mitigate the security issue.

To Reproduce
Steps to reproduce the behavior:

1. Install latest @useoptic/rulesets-base
2. Use a security scanner to analyze the dependencies
3. find that lodash.pick 4.4.0 has a security vulnerability

Expected behavior
@useoptic/rulesets-base doesn't ship with dependencies that have known security issues.

Additional context
Description of security vulnerability in lodash:
https://avd.aquasec.com/nvd/2020/cve-2020-8203/

[paras-verma7454]

we can write a function to replace lodash.pick

export function pick<T extends object, K extends keyof T>( obj: T, ...keys: K[] ): Pick<T, K> {
  const result = {} as Pick<T, K>;

  for (const key of keys) {
    if (Object.prototype.hasOwnProperty.call(obj, key)) {
      result[key] = obj[key];
    }
  }

  return result;
}

usage

// before
// import pick from 'lodash.pick';

// after
import { pick } from './utils/pick';

const sanitizeFact = (fact: IFact): IFact =>
  pick(fact, 'value', 'location') as IFact;

const sanitizeChange = (change: IChange): IChange =>
  pick(change, 'changeType', 'added', 'removed', 'changed', 'location') as IChange;

I can create a PR for this