search_date period separator support

[gavishpoddar]

This PR solves the below issues, it adds support for date objects like 12.12.2000 (separated by .)

• Search dates fails depending on whitespaces around prefix ":" #768
• Search date fails with different separator #771
• search_dates not recognizing dd.mm.yyyy #500
• search_dates : Issues paring dates with period #952
• Search dates fails with french language selector if string contains "-" #767

Tests are added for these cases

Thanks and Pl suggest if changes are required

Originally from #963

[codecov]

Codecov Report

❌ Patch coverage is 96.31902% with 6 lines in your changes missing coverage. Please review.
✅ Project coverage is 98.10%. Comparing base (507dc6d) to head (b54890e).
⚠️ Report is 133 commits behind head on master.

Files with missing lines	Patch %	Lines
dateparser/search/search.py	94.33%	6 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #963      +/-   ##
==========================================
- Coverage   98.29%   98.10%   -0.19%     
==========================================
  Files         234      235       +1     
  Lines        2694     2698       +4     
==========================================
- Hits         2648     2647       -1     
- Misses         46       51       +5     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[gavishpoddar]

This PR is currently broken