fix:(module:datepicker): Exception on input with time when Value is null

[Alexbits]

🤔 This is a ...

• New feature
• Bug fix
• Site / documentation update
• Demo update
• Component style update
• Bundle size optimization
• Performance optimization
• Refactoring
• Code style optimization
• Test Case
• Branch merge
• Other (about what?)

🔗 Related issue link

#2915

💡 Background and solution

Fixes InvalidOperationException in the DatePicker/RangePicker (with time input enabled) that happens after clicking the input field when Value is null.

📝 Changelog

Language	Changelog
🇺🇸 English
🇨🇳 Chinese

☑️ Self Check before Merge

⚠️ Please check all items below before review. ⚠️

• Doc is updated/provided or not needed
• Demo is updated/provided or not needed
• Changelog is provided or not needed

[github-actions]

[codecov]

Codecov Report

Base: 43.51% // Head: 45.00% // Increases project coverage by +1.48% 🎉

Coverage data is based on head (1a70b6f) compared to base (e9382b8).
Patch coverage: 69.23% of modified lines in pull request are covered.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2920      +/-   ##
==========================================
+ Coverage   43.51%   45.00%   +1.48%     
==========================================
  Files         551      551              
  Lines       25922    25919       -3     
  Branches      263      263              
==========================================
+ Hits        11281    11664     +383     
+ Misses      14601    14215     -386     
  Partials       40       40              

Impacted Files	Coverage Δ
...e-picker/internal/DatePickerDatetimePanel.razor.cs	73.91% <69.23%> (-0.82%)	⬇️
components/select/Select.razor.cs	53.24% <0.00%> (+0.26%)	⬆️
components/select/SelectBase.cs	71.19% <0.00%> (+0.27%)	⬆️
components/input/Input.cs	69.23% <0.00%> (+0.34%)	⬆️
components/date-picker/internal/DatePickerBase.cs	79.01% <0.00%> (+0.66%)	⬆️
components/core/CssSizeLength.cs	86.07% <0.00%> (+1.07%)	⬆️
components/grid/Col.razor.cs	96.00% <0.00%> (+1.33%)	⬆️
components/drawer/Drawer.razor.cs	93.50% <0.00%> (+3.24%)	⬆️
components/core/Extensions/JSRuntimeExtensions.cs	53.33% <0.00%> (+3.33%)	⬆️
components/grid/Row.razor.cs	84.44% <0.00%> (+8.88%)	⬆️
... and 11 more

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.