extension falls back to binary when the supplied Java version is < 11, and doesn't alert the user to this

[datho7561]

We should alert the user that the binary is being used if they have specified an outdated JVM to run the extension. Currently the binary is automatically used without any warning, and the only way to tell it's being used is to check the language server logs.

[rgrunber]

Also, the thing to be aware is when we fall back to the binary, if the binary is not trusted for some reason, they currently only see a prompt asking them whether they trust it. It's just a bit of a confusing prompt if you have no idea that in invalid Java version triggers the fallback. At the end of it, if the binary fails to load you get a message telling you it failed and that no Java was found. Maybe it should mention that no valid Java version was found.