Allow passing Parameter instances to Param pane

[philippjfr]

This is a bit of convenience to easily add single parameter widgets, i.e. this code:

 pn.pane.Param(parameterized, parameters=['parameter'], show_name=False)

becomes:

pn.pane.Param(parameterized.param.parameter)

[codecov-io]

Codecov Report

Merging #303 into master will increase coverage by 0.03%.
The diff coverage is 100%.

@@            Coverage Diff            @@
##           master    #303      +/-   ##
=========================================
+ Coverage   89.26%   89.3%   +0.03%     
=========================================
  Files          63      63              
  Lines        6504    6528      +24     
=========================================
+ Hits         5806    5830      +24     
  Misses        698     698

Impacted Files	Coverage Δ
panel/param.py	92.12% <100%> (+0.1%)	⬆️
panel/tests/test_param.py	99.66% <100%> (+0.01%)	⬆️

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[jbednar]

From the code, it looks like this would also work?

pn.Column(parameterized.param.param1, parameterized.param.param2)

That seems like a more common pattern than pn.pane.Param(parameterized.param.param1). But then there would be no label for each widget?

[philippjfr]

That seems like a more common pattern than pn.pane.Param(parameterized.param.param1). But then there would be no label for each widget?

Why wouldn't there be? Are you referring to show_name=False? That controls whether there is a label for the parameterized as a whole not for the individual parameter.

[jbednar]

Sounds good!