power and log simplifications return wrong results for base 1, 0 or negative

[RyanLin5967]

Describe the bug

Currently, power/log rewrites check the base's nullability but not its value, so degenerate bases fold wrong.

To Reproduce

CREATE VIEW nn AS SELECT * FROM (VALUES (1.0), (0.0), (-2.0), (2.0)) s(a);
CREATE VIEW nb AS SELECT a FROM (VALUES (1.0),(0.0),(-2.0),(2.0),(NULL)) s(a) WHERE a IS NOT NULL;
CREATE VIEW t  AS SELECT * FROM (VALUES (2.0), (3.0)) s(b);

SELECT a, log(a, 1.0), log(a, a) FROM nn;
-- 0.0 and 1.0 on all four rows, a = 1.0, 0.0 and -2.0 included

SELECT a, log(a, 1.0), log(a, a) FROM nb;
-- NaN NaN / -0.0 NaN / NaN NaN / 0.0 1.0, so only the schema's nullability differs

SELECT b, power(1.0, log(1.0, b)), log(1.0, power(1.0, b)) FROM t;
-- both b; should be 1.0 and NaN

SELECT count(*) FROM t WHERE power(1.0, log(1.0, b)) = 2.0;
-- 1, should be 0

SELECT power(1.0, log(1.0, 2.0)), log(1.0, 2.0);
-- 1.0 and inf, so the all-literal form is evaluated rather than rewritten

Expected behavior

What the nullable-base rows already print: NaN where the identity does not hold, and 1.0 for power(1.0, log(1.0, b)).

Additional context

The four are power(a, log(a,b)), log(a,1), log(a,a) and log(a, power(a,b)), each gated only on !base_nullable.

All four hold only for a > 0, a != 1.

datafusion 55.0.0