Table: Fixed incorrect async code path for label sorting

[uhfath]

Description

This PR fixes incorrect usage of async code path when clicking MudTable labels to sort data.
Also fixed double callback for ServerData in the same case.

How Has This Been Tested?

All standard tests apply and passed.

Types 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)

Checklist:

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

This PR was created based on 5.2.0 tag.

[codecov]

Codecov Report

Merging #3352 (89cd080) into dev (c60d577) will increase coverage by 0.05%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##              dev    #3352      +/-   ##
==========================================
+ Coverage   89.71%   89.77%   +0.05%     
==========================================
  Files         312      312              
  Lines        9507     9503       -4     
==========================================
+ Hits         8529     8531       +2     
+ Misses        978      972       -6     

Impacted Files	Coverage Δ
...Blazor/Components/Table/MudTableSortLabel.razor.cs	91.17% <100.00%> (+2.28%)	⬆️
src/MudBlazor/Components/Table/TableContext.cs	98.50% <100.00%> (ø)
...c/MudBlazor/Components/ChipSet/MudChipSet.razor.cs	90.24% <0.00%> (-0.31%)	⬇️
src/MudBlazor/Components/Button/MudFab.razor	100.00% <0.00%> (ø)
src/MudBlazor/Components/Button/MudFab.razor.cs	100.00% <0.00%> (ø)
src/MudBlazor/Components/Select/MudSelect.razor.cs	95.64% <0.00%> (ø)
...r/Components/Autocomplete/MudAutocomplete.razor.cs	91.87% <0.00%> (ø)
src/MudBlazor/Components/Input/MudInput.razor.cs	85.45% <0.00%> (+3.63%)	⬆️
src/MudBlazor/Extensions/TaskExtensions.cs	55.55% <0.00%> (+16.66%)	⬆️

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[JonBunator]

Thanks!
Can you please also add a bUnit test?

[uhfath]

Added a couple of tests to count the number of callbacks used.

[JonBunator]

Looks good! Thanks

[uhfath]

@JonBunator just out of curiosity, could you please comment on the Context thing?
It's just that I see a lot of pieces of code where Context is assumed to be null but don't know in which case that's possible.