Description:

This PR contains the following changes to the Mail configuration UI:

• As soon as the hostname is changed, the password will be cleared (unless the password has already been changed before)
• Focusing the password field will automatically select all it's content (if the password hadn't been changed already)

Review

• Functional review done
• Potential edge cases thought about (behavior of the code with strange input, with strange internal state or possible interactions with other Matomo subsystems)
• Usability review done (is anything maybe unclear or think about anything that would cause people to reach out to support)
• Security review done
• Wording review done
• Code review done
• Tests were added if useful/possible
• Reviewed for breaking changes
• Developer changelog updated if needed
• Documentation added if needed
• Existing documentation updated if needed