refactor(examples): switch all examples from { Delphi} to { ObjFPC}{+}

  - Switch all 4 console examples and all GUI example files to { ObjFPC}{+}
  - Add @ prefix to method pointer assignments (ObjFPC requirement)
  - Add @ prefix to Synchronize() calls in FileEncrypt thread
  - Add { Delphi} to dcpbase64.pas and dcpconst.pas (were missing it)
  - Remove -Mdelphi from Makefile FPCFLAGS_EX and CI release template
  - Update all documentation (.md, .txt, COMPILER.md, ci.yml) accordingly

DCPcrypt v2.0.5 - Lazarus/Free Pascal edition

  - 20 ciphers, 10 hashes, Base64, 6 block cipher modes
  - 282 automated tests
  - Docker-based Linux CI pipeline
  - GUI examples with screenshots
  - MIT license, fully documented