Fix a flickering issue when the timeline datasource is reloaded.

[nimau]

This PR fixes #7523

When the MXKRoomDataSource was reloaded, the tableView was refreshed immediately after the reset, showing a blank screen.
With this fix, the tableView is refreshed at the end of the reload method, which prevents a blank screen from appearing.

The MXKRoomDataSource resetNotifying method no longer seems necessary with this fix, as the original reset method was only called from:

• MXKRoomDataSource::reload
• MXKRoomDataSource::destroy: in this case its delegate is already nil

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
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No Coverage information
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[codecov]

Codecov Report

Patch coverage has no change and project coverage change: -0.01 ⚠️

Comparison is base (c9e9bd0) 12.37% compared to head (bc3c1b2) 12.37%.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #7528      +/-   ##
===========================================
- Coverage    12.37%   12.37%   -0.01%     
===========================================
  Files         1646     1646              
  Lines       163364   163361       -3     
  Branches     67078    67077       -1     
===========================================
- Hits         20218    20214       -4     
- Misses      142482   142484       +2     
+ Partials       664      663       -1     

Flag	Coverage Δ
uitests	55.06% <ø> (ø)
unittests	6.21% <0.00%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...rify/SAS/Views/VerifyEmojiCollectionViewCell.swift	0.00% <0.00%> (ø)
.../Modules/MatrixKit/Models/Room/MXKRoomDataSource.m	12.76% <0.00%> (-0.13%)	⬇️
...MatrixKit/Utils/EventFormatter/MXKEventFormatter.m	16.94% <0.00%> (ø)
.../SetPinCode/SetPinCoordinatorBridgePresenter.swift	0.00% <0.00%> (ø)

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[stefanceriu]

lgtm ¯_(ツ)_/¯