Revert CSM particles commit to fix particle spawner bug for 5.0.0 (#8288)

Reverts 5dab742645
"[CSM] Add functions to create particles and particlespawners."

doc/client_lua_api.txt

@@ -789,16 +789,6 @@ Call these functions only at load time!
       should listen from incoming messages with `minetest.register_on_modchannel_message`
       call to receive incoming messages. Warning, this function is asynchronous.
 
-### Particles
-* `minetest.add_particle(particle definition)`
-
-* `minetest.add_particlespawner(particlespawner definition)`
-    * Add a `ParticleSpawner`, an object that spawns an amount of particles over `time` seconds
-    * Returns an `id`, and -1 if adding didn't succeed
-
-* `minetest.delete_particlespawner(id)`
-    * Delete `ParticleSpawner` with `id` (return value from `minetest.add_particlespawner`)
-
 ### Misc.
 * `minetest.parse_json(string[, nullvalue])`: returns something
     * Convert a string containing JSON data into the Lua equivalent
@@ -1318,58 +1308,3 @@ Displays distance to selected world position.
 * `text`: Distance suffix. Can be blank.
 * `number:` An integer containing the RGB value of the color used to draw the text.
 * `world_pos`: World position of the waypoint.
-
-### Particle definition (`add_particle`)
-
-    {
-        pos = {x=0, y=0, z=0},
-        velocity = {x=0, y=0, z=0},
-        acceleration = {x=0, y=0, z=0},
-    --  ^ Spawn particle at pos with velocity and acceleration
-        expirationtime = 1,
-    --  ^ Disappears after expirationtime seconds
-        size = 1,
-        collisiondetection = false,
-    --  ^ collisiondetection: if true collides with physical objects
-        collision_removal = false,
-    --  ^ collision_removal: if true then particle is removed when it collides,
-    --  ^ requires collisiondetection = true to have any effect
-        vertical = false,
-    --  ^ vertical: if true faces player using y axis only
-        texture = "image.png",
-    --  ^ Uses texture (string)
-        animation = {Tile Animation definition},
-    --  ^ optional, specifies how to animate the particle texture
-        glow = 0
-    --  ^ optional, specify particle self-luminescence in darkness
-    }
-
-### `ParticleSpawner` definition (`add_particlespawner`)
-
-    {
-        amount = 1,
-        time = 1,
-    --  ^ If time is 0 has infinite lifespan and spawns the amount on a per-second base
-        minpos = {x=0, y=0, z=0},
-        maxpos = {x=0, y=0, z=0},
-        minvel = {x=0, y=0, z=0},
-        maxvel = {x=0, y=0, z=0},
-        minacc = {x=0, y=0, z=0},
-        maxacc = {x=0, y=0, z=0},
-        minexptime = 1,
-        maxexptime = 1,
-        minsize = 1,
-        maxsize = 1,
-    --  ^ The particle's properties are random values in between the bounds:
-    --  ^ minpos/maxpos, minvel/maxvel (velocity), minacc/maxacc (acceleration),
-    --  ^ minsize/maxsize, minexptime/maxexptime (expirationtime)
-        collisiondetection = false,
-    --  ^ collisiondetection: if true uses collision detection
-        collision_removal = false,
-    --  ^ collision_removal: if true then particle is removed when it collides,
-    --  ^ requires collisiondetection = true to have any effect
-        vertical = false,
-    --  ^ vertical: if true faces player using y axis only
-        texture = "image.png",
-    --  ^ Uses texture (string)
-    }