On very high traffic Piwik servers, prevent integer overflow by making...

On very high traffic Piwik servers, prevent integer overflow by making auto_increment fields BIGINT UNSIGNED (#10548)

* Change Latitude and Longitude data types to DECIMAL instead of FLOAT

* Add system test that forces an integer overflow, currently failing as expected

* Make all overflow-able fields BIGINT UNSIGNED

* Make overflow-able fields BIGINT UNSIGNED

* These fields were not covered by the new SimulateAutoIncrementIntegerOverflow test

* fix comment

* Make it clear that id* fields are UNSIGNED when installing Piwik

* BIGINT(10) for consistency

* Update core fields to BIGINT

* UI tests: New fields to be updated to bigint