Ensure edit_readonly resets class and instance level parameters

[maximlt]

Fixes #7999

Code adapted from edit_constant's code in Param. Example from the issue:

from panel.util.parameters import edit_readonly
import param

class Container(param.Parameterized):
    constant = param.Number(default=0, constant=True)
    readonly = param.Number(default=1, readonly=True)

obj = Container()

with edit_readonly(obj):
    obj.constant = 2
    obj.readonly = 3


print(f"{obj.constant = }, {obj.param.constant.constant = }, {obj.param.constant.readonly = }")
print(f"{obj.readonly = }, {obj.param.readonly.constant = }, {obj.param.readonly.readonly = }")

Output before:

obj.constant = 2, obj.param.constant.constant = False, obj.param.constant.readonly = False
obj.readonly = 3, obj.param.readonly.constant = False, obj.param.readonly.readonly = False

Output now:

obj.constant = 2, obj.param.constant.constant = True, obj.param.constant.readonly = False
obj.readonly = 3, obj.param.readonly.constant = True, obj.param.readonly.readonly = True

We should upstream this sort of utility to Param, maybe with some API improvements (e.g. should only act on readonly parameters, allow to specify a subset of parameters, make it available on the .param namespace).

[codecov]

Codecov Report

❌ Patch coverage is 85.29412% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 86.10%. Comparing base (d605c2b) to head (7b49b13).
⚠️ Report is 8 commits behind head on main.

Files with missing lines	Patch %	Lines
panel/util/parameters.py	85.29%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #8371      +/-   ##
==========================================
- Coverage   86.10%   86.10%   -0.01%     
==========================================
  Files         349      349              
  Lines       54709    54747      +38     
==========================================
+ Hits        47108    47138      +30     
- Misses       7601     7609       +8     

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[github-actions]

This pull request has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.