Add DateRangePicker widget

[TheoMathurin]

Replaces #2804
Closes #5844 and maybe #3789

As far as I know this reuse of Bokeh's implementation works fine.

As it's my first widget addition I'm open to suggestions to get closer to existing practices.

A small code to try it:

import datetime as dt
import panel as pn
import panel.widgets as pnw


def display_value(event):
    col.append(date_range_picker.value)


def set_value(event):
    date_range_picker.value = (dt.date(2019, 1, 2), dt.date(2019, 1, 5))


def set_start_end(event):
    date_range_picker.start = dt.date(2020, 1, 2)
    date_range_picker.end = dt.date(2020, 2, 5)


date_range_picker = pnw.DateRangePicker(name='Date Range Picker', start=dt.date(2019, 1, 1), end=dt.date(2019, 1, 10))
button1 = pnw.Button(name='Display Value', on_click=display_value)
button2 = pnw.Button(name='Set Value', on_click=set_value)
button3 = pnw.Button(name='Set start end', on_click=set_start_end)

row = pn.Row(date_range_picker, pn.Column(button1, button2, button3))
col = pn.Column(row)

col.servable()

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (fb36731) 84.68% compared to head (90f15cb) 72.89%.

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #6027       +/-   ##
===========================================
- Coverage   84.68%   72.89%   -11.79%     
===========================================
  Files         291      291               
  Lines       43730    43793       +63     
===========================================
- Hits        37032    31924     -5108     
- Misses       6698    11869     +5171     

Flag	Coverage Δ
ui-tests	?
unitexamples-tests	72.89% <100.00%> (+0.04%)	⬆️

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[philippjfr]

Looks great!

[fmfreeze]

@philippjfr may I ask, when this Daterangepicker is available in an official release?

And does it also support single date picking (start_date = end_date)? This is currently not supported by pn.widgets.DatetimeRangePicker when disabling time functionality.

[philippjfr]

Tagging 1.4.0rc1 on Monday so hopefully over the course of next week.

[philippjfr]

On the second part I'd have to check, you could try it out with 1.4.0b2 today.

[fmfreeze]

On monday i will try with 1.4.0b2, thank you!

[TheoMathurin]

Same day selection is supported.