Display Nepali (Bikram Sambat) calendar in reports filter

[dianabarsan]

What feature do you want to improve?
In the CHT platform, when the language is set to Nepali, the Bikram Sambat calendar is displayed in most areas. However, the date filter in the Reports tab still uses the Gregorian calendar, though displayed in the Nepali language.

Describe the improvement you'd like
Use the Nepali (Bikram Sambat) calendar in the Reports filter.
Integrating the Nepali (Bikram Sambat) calendar into the Reports tab would make it more user-friendly and consistent, allowing users to filter data more easily.

Additional context
Copy-pasted from a forum post: https://forum.communityhealthtoolkit.org/t/display-nepali-bikram-sambat-calendar-in-reports-filter/4451

cc @bhishankc , thanks for reporting!