feat(toastr): add duplicates behavior

[elupanov]

Please read and mark the following check list before creating a pull request:

• I read and followed the CONTRIBUTING.md guide.
• I read and followed the New Feature Checklist guide.

Short description of what this resolves:

Adds toaster service duplication behaviour

[codecov]

Codecov Report

Merging #1628 into master will increase coverage by 0.16%.
The diff coverage is 83.33%.

@@            Coverage Diff             @@
##           master    #1628      +/-   ##
==========================================
+ Coverage   83.29%   83.46%   +0.16%     
==========================================
  Files         231      231              
  Lines        7543     7552       +9     
  Branches      658      661       +3     
==========================================
+ Hits         6283     6303      +20     
+ Misses       1069     1055      -14     
- Partials      191      194       +3

Impacted Files	Coverage Δ
...framework/theme/components/toastr/toastr-config.ts	95% <100%> (+0.26%)	⬆️
...ramework/theme/components/toastr/toastr.service.ts	85.32% <81.81%> (+12.05%)	⬆️

[nnixaa]

@elupanov we would need some tests for this new functionality