Added form validation when creating a new device model

[audserraCGI]

Description

What's new?

• Bug: Form validation issue when creating a new device model #325

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Documentation content changes
• Tests
• Other

[codecov]

Codecov Report

Merging #392 (665d4ba) into main (a693b52) will decrease coverage by 0.58%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##             main     #392      +/-   ##
==========================================
- Coverage   50.29%   49.70%   -0.59%     
==========================================
  Files         101      101              
  Lines        2895     2929      +34     
==========================================
  Hits         1456     1456              
- Misses       1439     1473      +34     

Impacted Files	Coverage Δ
...ent/Pages/DeviceModels/CreateDeviceModelPage.razor	0.00% <0.00%> (ø)
...lient/Pages/DeviceModels/DeviceModelListPage.razor	48.57% <ø> (ø)
...s/DeviceModels/LoRaWAN/CreateLoraDeviceModel.razor	0.00% <0.00%> (ø)

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