Add CreateDatabase for embedded client

[rfx77]

Please add the feature to create a database with the embedded client. now i have to use isql to do this. otherwise i get an error

let mut conn =
        rsfbclient::builder_native()
            .with_dyn_load("C:\\develop\\libs\\fb\\fbclient.dll")
            .with_embedded()
            .db_name("test123.fdb")
            .user("SYSDBA")
            .connect()?;

Gives this Error.

Error: Sql { msg: "I/O error during \"CreateFile (open)\" operation for file \"test123.fdb\"\nError while trying to open file\nDas System kann die angegebene Datei nicht finden. ", code: -902 }
error: process didn't exit successfully: `target\debug\rust01.exe` (exit code: 1)

[fernandobatels]

I'm going to check the firebird API guide and try to implement this.

[fernandobatels]

@rfx77

create_database() is avaliable for use now