Strip whitespaces from host in ping config flow

[jpbede]

Proposed change

Strip leading and trailing whitespaces from host in ping config flow to avoid constantly "disconnected" entities.
Fixed the options flow test as well, it didn't made much sense how it was done.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Deprecation (breaking change to happen in the future)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes Whitespace in ping host causes ping to never be Connected state #130952
• This PR is related to issue:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
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