[WIP] updates for BPX v0.4.0 compatibility (#3414)

* use partial to get parameters in loop, add user-defined

* add support for blended electrodes

* add tests for bpx-0-4-0 for blended electrodes and user-defined parameters

* update CHANGELOG

* coverage

CHANGELOG.md

@@ -1,14 +1,19 @@
 # [Unreleased](https://github.com/pybamm-team/PyBaMM/)
 
+## Features
+
+- Add support for BPX version 0.4.0 which allows for blended electrodes and user-defined parameters in BPX([#3414](https://github.com/pybamm-team/PyBaMM/pull/3414))
+- Added the ability to specify a custom solver tolerance in `get_initial_stoichiometries` and related functions ([#3714](https://github.com/pybamm-team/PyBaMM/pull/3714))
+
 ## Bug Fixes
 
 - Updated `_steps_util.py` to throw a specific exception when drive cycle starts at t>0 ([#3756](https://github.com/pybamm-team/PyBaMM/pull/3756))
 - Updated `plot_voltage_components.py` to support both `Simulation` and `Solution` objects. Added new methods in both `Simulation` and `Solution` classes for allow the syntax `simulation.plot_voltage_components` and `solution.plot_voltage_components`. Updated `test_plot_voltage_components.py` to reflect these changes ([#3723](https://github.com/pybamm-team/PyBaMM/pull/3723)).
 - The SEI thickness decreased at some intervals when the 'electron-migration limited' model was used. It has been corrected ([#3622](https://github.com/pybamm-team/PyBaMM/pull/3622))
 
-## Features
+## Breaking changes
 
-- Added the ability to specify a custom solver tolerance in `get_initial_stoichiometries` and related functions ([#3714](https://github.com/pybamm-team/PyBaMM/pull/3714))
+- Dropped support for BPX version 0.3.0 and below ([#3414](https://github.com/pybamm-team/PyBaMM/pull/3414))
 
 # [v24.1rc2](https://github.com/pybamm-team/PyBaMM/tree/v24.1rc2) - 2024-01-24