Adding public functions addItems and setItems

[Lynesth]

The addItems one is simply an extension of addItem.
The setItems one allow to completly change the content of the menu by replacing all items.

I use setItems mainly when showing paginated lists so that I just create new items and shove them inside the menu, without rebuild it entirely.

[codecov-io]

Codecov Report

Merging #86 into master will decrease coverage by 0.87%.
The diff coverage is 0%.

@@             Coverage Diff             @@
##             master     #86      +/-   ##
===========================================
- Coverage     96.47%   95.6%   -0.88%     
- Complexity      278     282       +4     
===========================================
  Files            22      22              
  Lines           879     887       +8     
===========================================
  Hits            848     848              
- Misses           31      39       +8

Impacted Files	Coverage Δ	Complexity Δ
src/CliMenu.php	86.41% <0%> (-3.93%)	64 <4> (+4)

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[AydinHassan]

Thanks @Lynesth