Make setAnnotations could use custom className

[FavorMylikes]

Example

.ace_gutter-cell.ace_my_class_name{
    background: darkorange no-repeat 2px center;
}

editor.session.setAnnotations([{
                            row: 0,
                            text: ["some message will show when mouse hover"],
                            className: "ace_error"  // show the error icon
                        }, {
                            row: 0,
                            text: ["other message"],
                            className: "ace_my_class_name"  // show the background color instead of the default icon
                        }])

Issue #, if available:

Description of changes:

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[codecov]

Codecov Report

Merging #4362 into master will increase coverage by 0.01%.
The diff coverage is 91.66%.

@@            Coverage Diff             @@
##           master    #4362      +/-   ##
==========================================
+ Coverage   70.48%   70.50%   +0.01%     
==========================================
  Files         537      539       +2     
  Lines       54196    54230      +34     
  Branches    10199    10200       +1     
==========================================
+ Hits        38202    38234      +32     
- Misses      15994    15996       +2     

Flag	Coverage Δ
#unittests	70.50% <91.66%> (+0.01%)	⬆️

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

Impacted Files	Coverage Δ
lib/ace/layer/gutter.js	89.78% <75.00%> (-0.25%)	⬇️
lib/ace/mode/smithy.js	90.90% <90.90%> (ø)
lib/ace/mode/smithy_highlight_rules.js	100.00% <100.00%> (ø)
lib/ace/virtual_renderer.js	79.06% <100.00%> (ø)
lib/ace/range.js	85.51% <0.00%> (+0.68%)	⬆️

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