Added a default parameter maxIters to findEssentialMat and replaced the hardcoded value of 1000 in ransac_solvers.hpp. Fix for issue #22696

Test to check:

def roll():
    kpts0 = np.random.rand(2, 50)
    kpts1 = np.random.rand(2, 50)
    norm_thresh = .5
    conf = .5

    a = cv2.findEssentialMat(
        kpts0, kpts1, np.eye(3), threshold=norm_thresh, prob=conf, method=cv2.USAC_MAGSAC, maxIters = 1
    )

    b = cv2.findEssentialMat(
        kpts0, kpts1, np.eye(3), threshold=norm_thresh, prob=conf, method=cv2.USAC_MAGSAC, maxIters = 5000
    )
    return not (np.array_equal(a[0], b[0]) and np.array_equal(a[1], b[1]))


results_sum = sum([roll() for _ in range(10)])
print('Test failed' if results_sum == 0 else 'Test OK')

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