[SHIRO-789] Add SameSite option to AbstractShiroWebConfiguration.buildCookie

[bmarwell]

Functional changes:

• automatically set secure cookie on SameSiteOptions.NONE
• added test for the default value = LAX
• added test class for STRICT value

Other changes:

• add javadoc cookie description from developer.mozilla.org
• add missing overrides
• remove unused imports in AbstractShiroWebConfiguration and its test

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[bdemers]

Looks good! one minor comment about the signature change

[bmarwell]

retest this please

[bdemers]

(rebased on master)

[bdemers]

retest this please