Add support for catalog roles

[Flgado]

This PR adds support for specifying catalog roles in the Trino Go client via both the DSN string and the Config struct. Roles are passed as either:

• A map[string]string mapping catalogs to roles (e.g. {"hive": "analyst", "system": "admin"})

The roles are URL-encoded and appended to the DSN as a colon-separated list of catalog=ROLE{role} entries.

Example

// Using role map
c := &Config{
    ServerURI: "https://user@localhost:8080",
    Roles: map[string]string{"hive": "analyst", "system": "admin"},
}

using directly the dns connection

dns := ...?roles=catalog1:role1;catalog2:role2

[nineinchnick]

Why would we allow overriding roles in query parameters, instead of setting them for the whole connection? I think this should be only possible using SQL statements, and we actually should handle the X-Set-Role header coming back from the server (and remove it from unsupportedResponseHeaders).

[Flgado]

Yes, if we want to support it via DNS and use the JDBC format, we’ll need to find a way to convert it to the correct format. So, are you suggesting it should only be sent as an SQL statement? I’ll make the changes. 👍🏻
I also going to take a look to X-Set-Role thank you !

[nineinchnick]

Sorry, I got confused with the query variable - I thought it's for the user's SQL query, not the query part of the DSN URL. The check for =ROLE{ is also weird, this would mean we're adding support for some undocumented legacy format.

[Flgado]

AAAh I know what I have done wrong !
When I use the config and call the formatDNS function to setup the dns I am putting the right format already! And is not suppose

So here I am validation if is not on the right format already.

I will change it, I will convert it always to convert to jdbc format and then when it reach to this point I will convert it to the format that trino is waiting for: catalog=ROLE{role1},catalog=ROLE{rol2},