Feature request: Introduce alias to allow multiple svgs to be used simultaneously

[abid-mujtaba]

I am creating an animation where multiple messages (envelope svg) are moving around in a system. I would like to be able to use a single svg file but have multiple instances be present simultaneously but independently (each has their own position, opacity, and scale, etc.).

Currently this can be achieved by using symlinks to create multiple copies of the original svg file.

Suggest introducing an alias command which takes an svg name and creates an alias which from that point forward can be used similar to how the svg name is used directly.

Example (assuming a src/message.svg exists):

set_frame_size 600 300
alias message m1
alias message m2

place m1 0 100
animate_1000 pause
place m2 200 100 1 2