sympy symbol -> SR drops assumptions

[jdemeyer]

It is possible to add assumptions on sympy symbols:

sage: from sympy import Symbol
sage: n = Symbol("n", integer=True)

However, these are lost when converting to SR:

def _sympysage_symbol(self):
    """
    EXAMPLES::

        sage: from sympy import Symbol
        sage: assert x._sympy_() == Symbol('x')
        sage: assert x == Symbol('x')._sage_()
    """
    from sage.symbolic.ring import SR
    return SR.var(self.name)

This is the indirect cause for the different results below (based on a doctest in src/sage/tests/french_book/recequadiff.py):

sage: from sympy import Symbol, rsolve_hyper
sage: n = Symbol("n", integer=True)
sage: rsolve_hyper([-2,1], 2^(n+2), n)
2**n*C0 + 2**(n + 2)*(C0 + n/2)
sage: rsolve_hyper([-2,1], 2^(2+n), n)
2**n*C0 - 2**(n + 2)

Depends on #24067

CC: @rwst

Component: symbolics

Issue created by migration from https://trac.sagemath.org/ticket/24334

[jdemeyer]

Description changed:

--- 
+++ 
@@ -23,8 +23,8 @@
 This is the indirect cause for the different results below (based on a doctest in `src/sage/tests/french_book/recequadiff.py`):
 
 ```
+sage: from sympy import Symbol, rsolve_hyper
 sage: n = Symbol("n", integer=True)
-sage: from sympy import Symbol, rsolve_hyper
 sage: rsolve_hyper([-2,1], 2^(n+2), n)
 2**n*C0 + 2**(n + 2)*(C0 + n/2)
 sage: rsolve_hyper([-2,1], 2^(2+n), n)

[jdemeyer]

Dependencies: #24067