Standardise the use of Open and OpenChanged

[BieleckiLtd]

MudBlazor currently uses the IsOpen, IsOpened and IsOpenChanged properties. This PR aims to standardise the use of Open and OpenChanged to align with other boolean properties in the library.

Description

If this PR is approved, the v7 migration guide must also be updated, as this makes a breaking change:

MudAutocomplete: replace IsOpenChanged with OpenChanged
MudAutocomplete: replace IsOpen with Open
CellContext: replace IsOpened with Open
MudMenu: replace IsOpenChanged with OpenChanged
MudMenu: replace IsOpen with Open

Linked issues:
Negative property names should be discouraged #6131
v7.0.0 Migration Guide #8447

Standardise the use of IsEnabled and Enabled #8764
Standardise the use of ItemDisabled #8887
Standardise the use of Checked, CheckedChanged and Checkable #8825
Standardise the use of Visible #8832
Standardise the use of Selected and SelectedChanged #8886
Standardise the use of Expanded, Expandable, IsExpanded and IsExpandable #8718
Standardise the use of Active #8888
Standardise the use of Open and OpenChanged #8891
Standardise the use of Editable #8892
Standardise the use of Hidden and HiddenChanged #8952

How Has This Been Tested?

unit

Type of Changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation (fix or improvement to the website or code docs)

Checklist

• The PR is submitted to the correct branch (dev).
• My code follows the code style of this project.
• I've added relevant tests.

[henon]

Thanks!

Added to v7.0.0 Migration Guide #8447