[Bug]: Fix the Bug in `pybamm.QuickPlot.py` file

[Akhil-Sharma30]

PyBaMM Version

latest

Python Version

python3.11

Describe the bug

Took #3392 , This is a part of API Docs in this issue includes:

1. pybamm.QuickPlot.create_gif remove round brackets around optional keyword
2. pybamm.QuickPlot.dynamic_plot Args are optional
3. pybamm.QuickPlot.get_spatial_var Should be private (name start with underscore)
4. pybamm.QuickPlot.plot Document dynamic arg

Steps to Reproduce

Not applicable

Relevant log output

No response