Handling expression in location cast v2

[tkaratug]

This pull request introduces support for handling database expressions in the get() method of the LocationCast class, along with corresponding tests. The key updates include refactoring the get() method, adding a helper method for parsing expressions, and expanding test coverage to verify the new functionality.

Enhancements to LocationCast functionality:

• Added support for database expressions in the get() method by introducing a new private helper method, getCoordinates, to handle parsing of ST_GeomFromText expressions. (src/Casts/LocationCast.php: [1] [2]

Test coverage improvements:

• Added a new test, it_can_get_a_casted_attribute_using_expression, to validate that the get() method correctly processes attributes provided as database expressions. (tests/LocationCastTest.php: tests/LocationCastTest.phpR77-R94)
• Included the necessary Expression import to support the new test. (tests/LocationCastTest.php: tests/LocationCastTest.phpR5)

Documentation updates:

• Updated the CHANGELOG.md file to document the addition of expression support in the get() method for version 2.2.0. (CHANGELOG.md: CHANGELOG.mdR5-R7)