The public cvc5 API now lives in the cvc5 namespace. All internal parts were moved into the (new) internal namespace.
The final hierarchy will be as follows:
cvc5
~~ public API
::context
::internal
::parser
::main
After this PR it will be:
cvc5
~~ public API
::internal
::context
::main
::parser
This commit removes `Op::getIndices()`. As discussed offline, the
semantics of that method were confusing and the use cases are covered by
`Op::getNumIndices()` and `Op::operator[]()` (which mirror
`Term::getNumChildren()` and `Term::operator[]()`).
Future changes are going to update the Python and Java bindings to
support `Op::operator[]()`.
This renames the arithmetic internal and API kind PLUS to ADD for
consistency with our naming scheme for other operators (e.g.,
BITVECTOR_ADD, FLOATINGPOINT_ADD).
