[FEATURE] Redirect on confirmation

[mabolek]

• Introduces a TypoScript configuration option confirmationRedirectPid to specify what PID to redirect to, following successful subscription confirmation.

• Introduces a boolean TypoScript configuration option confirmationRedirectIncludeInfo, to enable the inclusion of fe_user uid and a validation hash to make sure the uid has not been changed by a third party.

• Moves hashing generation and validation into the class HashService. This gives a unified approach to hashing within the extension and avoids static parts of hashing strings being repeated in multiple places. It also enables third-party extensions to validate and generate validation strings more easily.

• Introduces functions in HashService to enable generation and validation of redirect hashes.

• Introduces a convenience function in HashService, validating a redirect hash in the GET parameters. This gives third-party extensions the possibility to validate a hash without knowing the names of the GET parameters used.

[mabolek]

@MattiasNilsson Should look better now.

[MattiasNilsson]

Nice 👍