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

Merging #963 (b54890e) into master (507dc6d) will decrease coverage by 0.18%.
The diff coverage is 96.31%.

@@            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     

Impacted Files	Coverage Δ
dateparser/search/search.py	94.73% <94.33%> (-4.64%)	⬇️
dateparser/languages/locale.py	98.71% <100.00%> (+0.02%)	⬆️
dateparser/search/__init__.py	100.00% <100.00%> (ø)
dateparser/search/languages.py	100.00% <100.00%> (ø)

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[gavishpoddar]

This PR is currently broken