Add not supported error description and checker logic

Add not supported error description and checker logic

- Issue:
New APIs are related with the TTS feature, but there is no information
about the feature in description of APIs.

- Solution:
This patch adds description for feature not supported error. And also,
this patch implements feature checker logic. Through this patch, the
APIs will not working if the feature is not enabled and return not
supported error.

Change-Id: I4c92376db2f98562c8792bc9446cb7a77d8a4626
Signed-off-by: Suyeon Hwang <stom.hwang@samsung.com>