Improve SKY pointing

At the moment only the boresigth direction can be retrieved in J2000 frame to get RA and DEC coordinates.

When present, it should be possible to retrieve these information for any instrument FOV bounds and display them as celestial coordinates on an global SKY map with the correct polygon wrapping if needed.

This should in DMS and HMS conversion tool and ticks:

def dms(alpha):
    """Convert angle in degree to Degrees Minutes Secondes"""
    d = abs(int(alpha))
    m = int((abs(alpha) - d) * 60)
    s = int((abs(alpha) - d - m / 60) * 3_600)
    return f'{np.sign(alpha) * d:+.0f}°{m:02d}m{s:02d}s'.removesuffix('00s').removesuffix('00m')

def hms(alpha):
    """Convert angle in degree to Hours Minutes Secondes"""
    hours = (alpha / 360 * 24) % 24
    h = np.uint8(np.round(hours, 3)) % 24
    m = np.uint8(np.round((hours - h) * 60, 3))
    s = np.uint8(np.round((hours - h - m / 60) * 3_600, 3))
    return f'{h}h{m:02d}m{s:02d}s'.removesuffix('00s').removesuffix('00m')