Add validator - "password"

[galhavivi]

Add a new validator to packages/form/src/validators.js file of "password".

• args (and defaultArgs) should include:
  "minLength" - default 8
  "maxLength" - default 20
  "minLetters" - default 0
  "minNumbers" - default 0
  "minSpecialCharachters" - default 0
  "minUppercase" - default 0
  "minLowecase" - default 0

• should have a matching error message depend on the args

• can use the second post from here to implement using regex: https://stackoverflow.com/questions/19605150/regex-for-password-must-contain-at-least-eight-characters-at-least-one-number-a

• should add unit test

• should add documentation in Form -> Validators -> Build in validators