fixes #17362

All three extensions are normally included in PHP when using the default compile parameters, but you can compile PHP without them, so it is possible that they are missing which breaks Matomo.

Weirdly the translation string for Installation_SystemCheckHashHelp already existed.

I also changed SystemCheckWarnJsonHelp as I doubt Matomo will work at all without json support. (and it is in the list of required extensions)

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 see checklist
• 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