Split and fix tst_searchengine

[rainemak]

Contains two commits

• Wait engine to load in initTestCase
• Split checkDefaultSearch of tst_searchengine to three

There are separate test functions for adding search engine, changing default,
and doing a search.

The dedicated test.xml is updated so that url is like qmoztest. This
way we can more easily compare url value. Actual search result is
irrelevant.

Further, test_003_searchFromWeb is skipped if there's no network
connection as it would time out easily when trying to do http get
without network to none existing service.

Requires:
sailfishos/embedlite-components#92

Whilst running tests locally noticed that test runner looks up installed search engines always from /home/defaultuser/.local/share/org.sailfishos/browser/searchEngines regardless of the active profile. The should be coming from here: https://github.com/sailfishos/gecko-dev/blob/master/embedding/embedlite/utils/DirProvider.cpp#L56 and there should be simple fix. Building engine with a fix applied and will open that PR shortly.

[rainemak]

This will fix the profile directory and look up. Following pref will dump look up path when there is an open search xml in the directory.

user_pref("browser.search.log", true);