evas/elm: fix visibility of some symbols

evas/elm: fix visibility of some symbols

Public symbols were defined internal to Evas/Elementary on macOS, making
the link of external modules unfeasible.

- EAPI was messed up by an invalid inclusion of evas_text_utils.h, making
  some symbols private instead of public.
- A similar issue was present in evas_font_draw.c, where the symbols
  were directly imported without the proper definition of EAPI.
- Elementary.h did include some eo-generated headers, but for windows
  only. It should not been restricted to windows, as it allows to export
  symbols to external modules.

Fixes T6448.