HMAC based token pattern

#### Support plan

* *is this issue currently blocking your project?* (yes/no):no
* *is this issue affecting a production system?* (yes/no):yes

#### Context

* *node version*: 12+
* *module version*: 8.0.1
* *environment* (e.g. node, browser, native):
* *used with* (e.g. hapi application, another framework, standalone, ...): Hapi application
* *any other relevant information*:

#### What problem are you trying to solve?

One of my project needed a stateless way to handle CSRF token, the customer's security team wanted us to implement the HMAC based token pattern as describe in the OWASP cheatsheet.

#### Do you have a new or modified API suggestion to solve the problem?
I did an implementation of the pattern and though it could be a great addition for the community, therefore I propose the pull request #155 to add this feature to CRUMB.