Separate Security Configuration

[mostafakhudair]

Creates new Config\Security class and make \CodeIgniter\Security\Security class depends on it

removes useless properties
rename some properties

rename some methods

CSRFVerify() to verify()
getCSRFHash() to getHash()
getCSRFTokenName() to getTokenName()
setHash() to generateHash()

add new public methods:

getHeaderName()
getCookieName()
isExpired()
shouldRedirect()

edits changes in user guide

• Securely signed commits
• Component(s) with PHPdocs
• User guide updated
• Conforms to style guide

Closes #3703

[mostafakhudair]

All green

[paulbalandan]

• Please squash commits 9ff90b9 to 6ab17ef.
• Squash commits 9df259b to 2bb5089.

We're now implementing a clean, descriptive commit history to help in changelog generation.

[mostafakhudair]

I'm working on it