momentary_door restarts movement sound repeatedly when moving back to starting position

[SamVanheer]

When a momentary_door moves back to its starting position its movement sound is constantly restarted.
Note that momentary doors don't move back by themselves. They move back because an associated momentary_rot_button is set to auto return.

See this video for an example in c2a3a: https://www.youtube.com/watch?v=hxPLKSjcWZA

This bug was fixed in Source with this fix: https://github.com/ValveSoftware/source-sdk-2013/blob/0d8dceea4310fde5706b3ce1c70609d72a38efdf/mp/src/game/server/func_movelinear.cpp#L253-L256

The same can be done for GoldSource.

After this line:

halflife/dlls/doors.cpp

Line 901 in c7240b9

void EXPORT DoorMoveDone( void );

Add this:

void EXPORT StopMoveSound();

Modify this:

halflife/dlls/doors.cpp

Lines 1048 to 1052 in c7240b9

	void CMomentaryDoor::DoorMoveDone( void )
	{
	STOP_SOUND(ENT(pev), CHAN_STATIC, (char*)STRING(pev->noiseMoving) );
	EMIT_SOUND(ENT(pev), CHAN_STATIC, (char*)STRING(pev->noiseArrived), 1, ATTN_NORM);
	}

To become this:

void CMomentaryDoor::DoorMoveDone()
{
	// Stop sounds at the next think, rather than here as another
	// Use call might immediately follow the end of this move
	//This think function will be replaced by LinearMove if that happens.
	SetThink(&CMomentaryDoor::StopMoveSound);
	pev->nextthink = pev->ltime + 0.1f;
}

void CMomentaryDoor::StopMoveSound()
{
	STOP_SOUND(ENT(pev), CHAN_STATIC, (char*)STRING(pev->noiseMoving));
	EMIT_SOUND(ENT(pev), CHAN_STATIC, (char*)STRING(pev->noiseArrived), 1, ATTN_NORM);
	SetThink(nullptr);
}

Not the same as #1235.