Use only relative paths in studio URLs.

[docbacardi]

What does this PR do?

Change absolute URLs in the studio to relative ones.

Motivation

Relative URLs in the studio eases the task to proxy multiple instances of ArcadeDB. Without this patch, URLs in the HTML and Javascript documents must be rewritten by the proxy. With this patch this is no longer necessary.

As an example the following nginx config snippet proxies 2 ArcadeDB instances:

        # This is the production instance.
        location /arcadedb/stable/ {
                rewrite ^/arcadedb/stable(.*)$ $1 break;
                proxy_pass http://10.11.12.13:2480;
        }
        # This is the sandbox server.
        location /arcadedb/sandbox/ {
                rewrite ^/arcadedb/sandbox(.*)$ $1 break;
                proxy_pass http://10.11.12.14:2480;
        }

Please note that the configuration example rewrites only the URL in the client's request. It does not change the URLs in the HTML and Javascript files sent by the ArcadeDB server.

Additional Notes

Unfortunately I'm too dumb to create a unit test for this. :(

Checklist

• I have run the build using mvn clean package command
• My unit tests cover both failure and success scenarios

[lvca]

It looks good to me, thanks or your contribution!