`extractUrl()` returns URL components from a source URL string. It does
this by matching the URL against regular expressions. The irrelevant
(entire URL) matches are removed and the rest stored as their
corresponding URL components in a POJO. The function uses the ufo module
to handle most of the parsing logic. The only custom behavior is using
the `useHttps` boolean to prepend a scheme to the source URL.

- `url` can be a partial, full URL, or full proxy URL.
- `useHttps` boolean defaults to false.

The function returns `{ protocol, auth, host, pathname, search, hash }`
POJO extracted from the URL.

This commit creates a static `_buildURL` method on the imgix client. The
method allows full URLs to be formatted for use with imgix.

> note: If the source URL has included parameters, they are merged with
the `params` passed in as an argument.

- `url`: full source URL path string, required
- `params`: imgix params object, optional
- `options`: imgix client options, optional

The method returns a URL string formatted to imgix specifications.

This commit creates a _buildSrcSet static method that allows full URLs
to be used when generating imgix formatted `srcset` string values.

- If the source URL has included parameters, they are merged with
the `params` passed in as an argument.
- URL must match `{host}/{pathname}?{query}` otherwise error is thrown.

`url` - full source URL path string, required
`params` - imgix params object, optional
`options` - imgix client options, optional

The method returns an imgix `srcset` for full URLs.

This commit refactors the options object into two objects, srcsetOptions and clientOptions for added clarity and better separation of concerns.

# [3.3.0-rc.1](v3.2.1...v3.3.0-rc.1) (2021-07-07)

### Features

* add srcsetModifiers and clientOptions params ([b0d6685](b0d6685))
* create extractUrl helper ([5a5048e](5a5048e))
* create static buildURL method ([9027a82](9027a82))
* static buildSrcSet method ([ea99366](ea99366))

 [skip ci]

# [3.3.0](v3.2.1...v3.3.0) (2021-07-08)

### Features

* add srcsetModifiers and clientOptions params ([b0d6685](b0d6685))
* create extractUrl helper ([5a5048e](5a5048e))
* create static buildURL method ([9027a82](9027a82))
* static buildSrcSet method ([ea99366](ea99366))

 [skip ci]