Rename parameters from "electrode" to "particle"

[julian-evers]

As "positive electrode diffusivity" is currently renamed to "positive particle diffusivity" it might be a good time to rename other parameters similarly as non-breaking changes with deprecation warnings, though that might not be perfect for film-type electrodes. How do you think about below parameter names?

• Initial concentration in positive particle [mol.m-3]
• Maximum concentration in positive particle [mol.m-3]
• Positive electrode Bruggeman coefficient (particle)
• Positive particle charge transfer coefficient
• Positive particle exchange-current density [A.m-2]

[valentinsulzer]

We're reviewing how parameters are defined as part of #3909 . Let's discuss there