SIH - change how LAT and LON is used for Takeoff location

[Claudio-Chies]

Solved Problem

for SIH the Lat and Long parameter was set in an inconsistent way, unlike how gazebo (before #22638) and gazebo classic handled it.
it used an int which it converted to a float, meaning if you copy and paste WGS84 coordinates you hat to manually remove the comma and add zeros.
PX4 Docs: PX4/PX4-user_guide#3275

Solution

change from int to float, allowing easy copy and paste of WGS84 coordinates.

Changelog Entry

For release notes:

Feature/Bugfix fix of inconsistent parameter handling for SIH
New parameter: -
Documentation: See PX4-Docs

Test coverage

Tested in SITL

[Jaeyoung-Lim]

Thanks!