[ANN] Release of UXStrings 0.6.0

[Blady]

This Ada library provides Unicode character strings of dynamic length.
It is now available on Alire [1] in version 0.6.0.

Changes:
- Add string convenient subprograms [2]: Contains, Ends_With,
Starts_With, Is_Lower, Is_Upper, Is_Basic, Is_Empty, Remove, Replace.
- Add list of strings with convenient subprograms [3]: Append_Unique,
Filter, Join, Remove_Duplicates, Replace, Slice, Sort, Is_Sorted, Merge
and Split on strings.
So far in UXStrings, its API are similar to those of the strings Ada
standard libraries. If you find some missing, make your proposals on Github.

NB: UXStrings3 is now the default implementation.

Enjoy, Pascal.

[1] https://alire.ada.dev/crates/uxstrings.html
[2]
https://github.com/Blady-Com/UXStrings/blob/master/src/uxstrings3.ads#L346
[3]
https://github.com/Blady-Com/UXStrings/blob/master/src/uxstrings-lists.ads
[4] https://github.com/Blady-Com/UXStrings/issues