Add `TaijaBase` and `Taija` package bundles

[pat-alt]

Discussed in https://github.com/orgs/JuliaTrustworthyAI/discussions/1

^{Originally posted by pat-alt May 31, 2023}

• Rename Taija to TaijaOrg.
• Add TaijaBase.jl and Taija.jl packages following the MLJBase.jl and MLJ.jl convention.

This would enable users to automatically load a base suite or full suite of packages. Additionally, could then easily add packages that add non-core functionality for many of our packages following the Tidier approach. For example:

• TaijaData.jl: load and prepare datasets. #4
• TaijaPlots.jl: implement plotting functionality for various packages. #3
• TaijaParallel.jl: add multi-processing support for various packages.
• TaijaInterop.jl: Support for interoperability