Add top missing antlr4 headers inside impl.

[hzeller]

One commit per header for easier review.

Done semi-automatically by taking the output of clang-tidy's misc-include-cleaner reports and inserting them where needed.

~/src/henner-tools/dev-tools/insert-header.cc 'tree/ParseTreeType.h' $(grep "no header providing.*misc-include-cleaner" Cpp_clang-tidy.out | awk -F: '/^runtime\/.*"antlr4::tree::ParseTreeType"/ { print $1}' | sort -u)

This is not done for all missing headers yet, some of the remaining reports point to cyclic dependencies that now work because everyone sees the forward declarations support/Declarations.h. My goal is minimize the reliance on these forward declarations and reach a good IWYU situation for a clear view of the internal dependencies.

Anyway, here a first round.

[hzeller]

FYI @parrt