Add mapReady to test case start conditions

It is reasonable to add mapReady property to the condition
for the start of test cases where it is required that the
map is initialized. This covers the case when one of the
initialization steps runs asynchronously.

Change-Id: I2eff52dbe3a7bec0b2f3fb26d607398829b5c9f2
Reviewed-by: Paolo Angelelli <paolo.angelelli@qt.io>