Fixed some Keccak testcases

[danielmarschall]

This PR contains 2 fixes:

1. It fixes a bug that was cause because an uninitialized variable LastByteLen instead of the argument LastByteLength was used.

2. I have reverted to AddLastByteForCodeTest(lDataRow, #$13, 5); again, now the test cases do work. I still have no clue why #$13 represents the test vector 0b10011, but for some reason it works. Maybe some day someone will find out why it works :-)
   Edit 12 Feb 2025: Regarding point 2, I don't understand why I was confused back then.
   0b10011 is 0x13 and Decimal 19. In Delphi hex numbers have a $ prefix, so both #$13 and #19 are correct, but not #$19.

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All test cases except the Unicode test case are working now. The Unicode test case might be impossible, though; see more details in #65

[danielmarschall]

3. I am just confused where the 0b10011 (which is dec19 / hex13) comes from in the first place. Is this documented somewhere? I think this should be added as a comment somewhere, so it is easier to understand.

4. I noticed that there is an "exit" at

   DelphiEncryptionCompendium/Unit Tests/Tests/TestDECHashSHA3.pas

   Line 1884 in 2e8d2ec

   exit;

   I am not sure if this is intentional or an oversight from debugging.

@MHumm What do you think?