Fix crashes when deleting items

[VMelnalksnis]

Fixes #1259

Changes proposed in this pull request:

• Use a command instead of binding to method
• Fix refreshes after deleting
• Merge ICommandFactory into IActivityService

[codecov]

Codecov Report

Attention: Patch coverage is 89.33333% with 8 lines in your changes missing coverage. Please review.

Project coverage is 70.62%. Comparing base (d2ec65c) to head (6a7ec10).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1332      +/-   ##
==========================================
+ Coverage   70.60%   70.62%   +0.01%     
==========================================
  Files         539      538       -1     
  Lines       13642    13636       -6     
  Branches     1047     1047              
==========================================
- Hits         9632     9630       -2     
+ Misses       3655     3653       -2     
+ Partials      355      353       -2     

Components	Coverage Δ
API	77.62% <ø> (ø)
UI	61.09% <89.33%> (+0.02%)	⬆️