[tizen] WebAPI{Exception|Error} constructors exported into global scope.

[tizen] WebAPI{Exception|Error} constructors exported into global scope.

For compliance reasons constructors should not be exported into tizen namespace,
but should be available internally to allow throwing exceptions from modules.

Change related to http://168.219.209.56/gerrit/#/c/23472/

[Verification] TCT pass rate:
- tizen 77/81 (all WebAPIException related TCs should pass)
- other modules - results without change

Change-Id: I58e5dc9932b24afc8516a37564ac1497618e709f