Removes the last remaining server dependencies from jdbc client. In order to do that it introduces the new project sql-shared-proto that contains only XContent-serializable classes. HTTP Client and JDBC now depend only on sql-shared-proto. I had to keep the original sql-proto project since it is used as a dependency by sql-cli and security integration tests.
Relates #29856
The bundled configuration isn't recognised by eclipse so these
dependencies are missed when it imports the `x-pack:plugin:sql:jdbc`
project. This change makes these dependencies compile dependencies if
the build is running for Eclipse.