[change] Renamed daterangepicker widget labels #487

[Aryamanz29]

Renamed date range widget label from last week, month and year to 7 days, 30 days and 365 days to avoid any misunderstandings in the future.

Closes #487

Checks:

• I have manually tested the proposed changes
• I have updated the documentation (e.g. README.rst)

[nemesifier]

Please flag the strings as translatable using gettext(), which should be already loaded in the global namespace (please double check).

[nemesifier]

Thanks 👍