I tried to improve radial waves class in many aspects

[Arch-User-0]

I thought the waves should propagate with time, have circular domain. In some cases, if there are several sources in a scene, it is needed to simulate a src start emitting waves while one src is already causing a wave to propagate. I could use functions like move_to() etc, but i wanted to do it with just maths, feel freee to change it if it leads to a better performance
Here are example files i got, i still plan to make it less cluttered in some cases (Eg-#2) but i dont see a way to do it yet with pure maths :

Eg: #1

class diffraction(ThreeDScene):

        def construct(self):

        self.set_camera_orientation(phi=15*DEGREES,theta=-120*DEGREES,zoom=0.7)
        self.renderer.camera.light_source.move_to(3 * OUT + 2*LEFT)

        plane_wave = LinearWave(amplitude=0.2,angular_frequency=2*PI,wavelength=1.5, x_range=[-8,2],y_range=[-3,3],    start_from=-7.5,cutoff_time=10/6)
        plane_wave.propagate_with_time()

        line_1 = Line(start=(2,6,0),end=(2,1.5,0))
        line_2 = Line(start=(2,-1.5,0),end=(2,-6,0))
        self.add(line_1,line_2)

        rad_wave = RadialWave(
    (0, -1.5, 0),
    (0, -1.35, 0),
    (0,  0.00, 0),
    (0,  1.325, 0),
    (0,  1.5, 0),
            amplitude=0.3,
            wavelength=1.5,
            angular_frequency=2*PI,
            x_range=[-5,5],
            y_range=[-5,5],
            shade_in_3d=True,
            stroke_width=0,
            start_when=1.35,
            angle_range=[-PI/2.2, PI/2.2],
            resolution=48
        )
        
        self.add(rad_wave,plane_wave)
        rad_wave.propogate_radially_with_time((2,0,0))
        self.wait(8)

Eg-#2

class interference(ThreeDScene):
    def construct(self):
        axes = ThreeDAxes()
        self.add(axes)

        self.set_camera_orientation(theta=35*DEGREES,phi=35*DEGREES,zoom=0.7)
        t=ValueTracker(0)
        wave_1 = RadialWave( 
            (0,0,0),
            amplitude=0.2,
            wavelength=3/4,
            angular_frequency=2*PI,
            x_range=[-5,5],
            y_range=[-5,5],
            stroke_width=0
        )
        # r_wave.start_updating_wave()
        
        wave_2 = RadialWave( 
            (3,4,0),
            amplitude=0.2,
            wavelength=3/4,
            angular_frequency=2*PI,
            x_range=[-5,5],
            y_range=[-5,5],
            stroke_width=0
        ).set_color(WHITE)
        wave_1.propogate_radially_with_time((0,0,0))
        wave_2.propogate_radially_with_time((3,4,0))

        net_wave = RadialWave( 
            (0,0,0),(3,4,0),
            amplitude=0.4,
            wavelength=3/4,
            angular_frequency=2*PI,
            x_range=[-3,3],
            y_range=[-3,3],
            stroke_width=0,
            start_when=np.sqrt(5)*4/3
        ).set_color(PINK)
        self.add(wave_1,wave_2,net_wave)
        
        net_wave.propogate_radially_with_time((1.5,2,0))
        
        self.wait(6)

You may not recognise some methods from LinearWave class as ive modified it too but i plan not to release it, yet
This is my first PR on github so sorry if i made formatting error or any other mistakes