FriCAS Code

Add VectorSpaceBasis domain.

Fix for 'has' test.

Ignore sign when deciding if number is prime.

Use linear solver for linear systems of expressions.

Remove wrong duplicate definitions of '^'.

Update comments.

add default implementation for convert()@INFORM to Finite.

add package call to make guessing over AN succeed. Add test demonstrating bad
gcd in GUESSP with four variables.

create default definition for random in Finite and use it.

new testsuite testing that lookup and index are inverses in domains with
Finite.