feat(bootstrap): update Action Bootstrap Dropdown formatter example

[ghiscoding]

superseeds #309 and enhance #304

@jeremielodi
Thanks for your contribution, this looks really nice and much more usable this way, also a lot easier to use.

[codecov]

Codecov Report

Merging #314 into master will increase coverage by 0.23%.
The diff coverage is 92.99%.

@@            Coverage Diff             @@
##           master     #314      +/-   ##
==========================================
+ Coverage   97.03%   97.25%   +0.23%     
==========================================
  Files         136      137       +1     
  Lines        7899     7698     -201     
  Branches     2583     2604      +21     
==========================================
- Hits         7664     7486     -178     
+ Misses        234      212      -22     
+ Partials        1        0       -1

Impacted Files	Coverage Δ
src/app/modules/angular-slickgrid/index.ts	100% <100%> (ø)	⬆️
...ular-slickgrid/modules/angular-slickgrid.module.ts	100% <100%> (ø)	⬆️
.../app/modules/angular-slickgrid/formatters/index.ts	100% <100%> (ø)	⬆️
...ngular-slickgrid/formatters/bsDropdownFormatter.ts	100% <100%> (ø)
...rc/app/modules/angular-slickgrid/services/index.ts	100% <100%> (ø)	⬆️
...s/angular-slickgrid/services/bsDropdown.service.ts	91.49% <91.49%> (ø)
...lickgrid/components/angular-slickgrid.component.ts	61.21% <0%> (-0.07%)	⬇️
...dules/angular-slickgrid/services/filter.service.ts	100% <0%> (ø)	⬆️
...dules/angular-slickgrid/sorters/sorterUtilities.ts	100% <0%> (ø)	⬆️
... and 10 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update cd53549...0b96746. Read the comment docs.