Deprecation of `emulate!` and migration to `solve` interface

[johnzl-777]

Which part of the documentation/examples?

• https://queracomputing.github.io/Bloqade.jl/dev/#A-Simple-Example
• https://queracomputing.github.io/Bloqade.jl/dev/emulation/
• Any tutorials that invoke emulate!

What content needs to be improved/added?

Changes planned by @Roger-luo should be documented:

• emulate! will be deprecated
• the solve interface from DifferentialEquations.jl will become the recommended and later sole method of simulating time evolution.

[johnzl-777]

Additional/narrowed requirements:

• Examples in the documentation using emulate! should be changed to use solve
• An "admonition" (see: https://documenter.juliadocs.org/stable/showcase/#Warning-admonition) should tell users that emulate! was the previously recommended method but will soon be deprecated
• A deprecation notice should be present in the API