[Starfish] Add db attributes to database span's span data

[AbhiPrasad]

To get an overview of this work across all SDKs, please visit:
https://github.com/orgs/getsentry/projects/135

Parent issue: getsentry/team-sdks#19

For the starfish db module it was determined that we need extra database attributes, specifically about the database connection attributes.

We're going to matching the otel db conventions. Either one of server.address or server.socket.address is required. If server.address is set, then server.port should be set. If server.port is different than server.socket.port, than server.socket.port should also be set. In addition, db.name should be set if possible. db.system should match the list in OpenTelemetry's well known conventions.

Attribute	Type	Description	Examples	Requirement Level
db.system	string	An identifier for the database management system (DBMS) product being used.	mysql	Required
server.address	string	Name of the database host.	example.com	Conditionally Required: See alternative attributes below.
server.port	int	Logical server port number	80; 8080; 443	Conditionally Required: [1]
server.socket.address	string	Physical server IP address or Unix socket address.	10.5.3.2	See below
server.socket.port	int	Physical server port.	16456	Recommended: If different than server.port.
db.name	string	This attribute is used to report the name of the database being accessed. For commands that switch the database, this should be set to the target database (even if the command fails).	customers; main	Conditionally Required: If applicable.

These values should be set on span.data.

Motivation

This is being done for the Sentry's new performance views for databases. See a WIP example of the view below: