[Cherry-pick] [EFL][WK2] Add ewk_settings APIs for text autosizing

[Cherry-pick] [EFL][WK2] Add ewk_settings APIs for text autosizing

[EFL][WK2] Add ewk_settings APIs for text autosizing
https://bugs.webkit.org/show_bug.cgi?id=103342

Reviewed by Kenneth Rohde Christiansen.

Add ewk_settings_text_autosizing_enabled_get / set() functions.
Text autosizing is disabled by default.

* UIProcess/API/efl/ewk_settings.cpp:
(ewk_settings_text_autosizing_enabled_set):
(ewk_settings_text_autosizing_enabled_get):
* UIProcess/API/efl/ewk_settings.h:
* UIProcess/API/efl/tests/test_ewk2_settings.cpp:
(TEST_F):

Change-Id: Id519d9fe9e983b3d61b83f0d393d0082c2c01c60