Clean up repo - delete disused libraries

[JimKerslake]

As warned in v8.3 release notes:

Bootstrap3 libraries should go.
BS4 left in place temporarily for reference.

The .pgsql libraries were superseded many moons ago by the .PostgreSql ones - the latter enforcing snake case conventions.
The .pgsql ones have not been kept up to date with recent schema changes, and are not delivered by the template - so really need to be gotten rid of.

This wants doing across all CS solutions...