fix: add bs-datepicker.css file to package.json exports

[salmoro]

This PR enables importing "bs-datepicker.css" file when using Yarn with PnP. When declared, the "exports" field in a package.json is meant to conceal and exclude all unspecified files or directories. Until now the exclusion of "bs-datepicker.css" wasn't an apparent issue because no other package manager/strategy is able to enforce disallowing importing files not specified in the "exports" field but Yarn with PnP enforces it.

https://nodejs.org/api/packages.html#packages_exports
https://github.com/jkrems/proposal-pkg-exports/
https://angular.io/guide/creating-libraries#managing-assets-in-a-library

fixes #6449

[codecov]

Codecov Report

Merging #6451 (a89d89d) into development (6be9fc4) will decrease coverage by 0.01%.
The diff coverage is n/a.

@@               Coverage Diff               @@
##           development    #6451      +/-   ##
===============================================
- Coverage        75.87%   75.85%   -0.02%     
===============================================
  Files              315      315              
  Lines            10642    10642              
  Branches          2935     2845      -90     
===============================================
- Hits              8075     8073       -2     
- Misses            2566     2568       +2     
  Partials             1        1              

Impacted Files	Coverage Δ
src/chronos/i18n/sk.ts	85.00% <0.00%> (-2.50%)	⬇️
src/chronos/i18n/cs.ts	87.36% <0.00%> (-2.11%)	⬇️
src/chronos/i18n/pl.ts	85.24% <0.00%> (ø)
src/chronos/i18n/uk.ts	90.62% <0.00%> (+3.12%)	⬆️

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[cypress]

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Test summary

799 • 33 • 14 • 0

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Run details

Project	ngx-bootstrap
Status	Failed
Commit	ce93725 ℹ️
Started	Apr 7, 2022 7:08 AM
Ended	Apr 7, 2022 7:43 AM
Duration	34:37 💡
OS	Linux Ubuntu - 20.04
Browser	Electron 93

View run in Cypress Dashboard ➡️

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Failures

	datepicker/locales_spec.ts		2
1	Datepicker demo testing suite: Locales > Change Locale Datepicker > when user chose locale es-pr for "Datepicker", container shown in appropriate language
2	Datepicker demo testing suite: Locales > Change Locale DateRangepicker > when user chose locale es-pr for "Daterangepicker", container shown in this language
	typeahead_page_spec.ts		1
1	Typeahead demo page testing suite > On blur > clicking anywhere outside auto-fills "Option on blur" with the first option from the matches list
	modals_service_page_spec.ts		7
1	Modals demo page testing suite: Service examples > Nested modals > when user clicks on the button "Open second modal" then the second modal with title "Second modal" is opened, "Close self" is present
2	Modals demo page testing suite: Service examples > Events > when user closes modal by click on the cross then should be messages "onHide event has been fired" and "onHidden event has been fired"
3	Modals demo page testing suite: Service examples > Events > when user closes modal by pressing ESC button then modal is closed and should be messages "onHide event has been fired" and "onHidden event has been fired"
4	Modals demo page testing suite: Service examples > Confirm Window > when user clicks on "Open modal" button then modal is opened, it contains two buttons: "Yes" and "No"
5	Modals demo page testing suite: Service examples > Custom css class > when user clicks on the cross button then the modal is closed
6	Modals demo page testing suite: Service examples > Animation option > when user clicks on the cross button then the modal is closed
7	Modals demo page testing suite: Service examples > Esc closing option > when user clicks on "Open modal" button then modal is opened. when user closes modal by click ESC button then modal stays opened
This comment includes only the first 10 test failures. See all 33 failures in the Cypress Dashboard.

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[valorkin]

thanks for your help:)