* Upgrade UXStrings to version 0.7.0.
Add UXStrings 4 implementation (Ada.Containers.Vectors).
Use scenario variables in project files for choosing between UXStrings implementation UXS_VARIANT=UXS1..4.
Add Keep_Empty_Parts default parameter to Split.
* Change GNAT required version.
* Bring back strings_edit source codes from Simple Components since dependancies of SC puzzled Alire.
* Suppress 0.7.0 as it puzzles Alire checks.
---------
Co-authored-by: Alejandro R Mosteo <amosteo@unizar.es>
* Add UXStrings library to Alire.
* Set minimal GNAT version for Alire.
* Change version format in conformance to https://semver.org.
Set UXStrings commit to some fixes.