Fix C++Builder compile errors on V7 compatibility constants

[zencode1]

The V7 backward-compatibility constants in VirtualTrees.pas (e.g. ctNone = VirtualTrees.Types.TCheckType.ctNone) alias scoped enum members. Without telling the C++ header generator about that, C++Builder users encounter ambiguity compiler errors when these are translated to .hpp.

This PR adds, for each constant in VirtualTrees.pas:

• {$EXTERNALSYM} - stops the .hpp generator from emitting a conflicting redeclaration for the symbol.
• {$HPPEMIT} - restores the plain, unscoped C++ alias

Additional changes:

• Grouped the constants by source enum with a comment for readability.
• Fixed csMixedDisable -> csMixedDisabled (typo - didn't match the enum member it was meant to alias).
• Removed the alignment spacing since it distracted from readability due to the grouped compiler directives

No runtime/behavior change - Delphi consumers are unaffected; this only fixes header generation for C++Builder.

Suggest any formatting changes if I didn't match the repository standards.