fix(build): provide ES5 code in UMD bundles

[yggg]

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Short description of what this resolves:

Closes #2469

[ghost]

DeepCode's analysis on #849ec5 found:

• ℹ️ 1 minor issue. 👇

Top issues

Description	Example fixes
Type declaration of 'any' loses type-safety. Consider replacing it with a more precise type. Occurrences: bundle.ts:46	🔧 Example fixes

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[codecov]

Codecov Report

Merging #2520 into master will increase coverage by 0.03%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2520      +/-   ##
==========================================
+ Coverage   78.92%   78.96%   +0.03%     
==========================================
  Files         253      253              
  Lines        7774     7774              
  Branches      852      852              
==========================================
+ Hits         6136     6139       +3     
+ Misses       1376     1372       -4     
- Partials      262      263       +1     

Impacted Files	Coverage Δ
...ramework/theme/components/toastr/toastr.service.ts	97.39% <0.00%> (+2.60%)	⬆️