[Feature] Error message if Java SDK is too old for JDTLS

[LDAP]

    Workaround: download a newer JDK and set "java.home" property in LSP-jdtls.settings, e.g. 

{
        "settings": {
                "java.home": "/usr/lib/jvm/java-19-openjdk/"
        }
}

Suggested change in LDP-jdtls; error message if java version is too old for jdtls?

Originally posted by @MFAshby in https://github.com/sublimelsp/LSP-jdtls/issues/21#issuecomment-1265204131