schema/inspect: support inspect for non-database resource

[giautm]

This PR updates the atlas schema inspect command to support other resources: sql-file, hcl-file, and Ent's schema. When you do inspect those resources, you need to provide a dev-DB for Atlas to replay changes on it.

With an unexpected side effect, to fix what we believe to be a bug with the inspect command. The --exclude flag when used with schema connection can only exclude sub-resources such as: table, column, index, ... and no longer exclude the current schema.

Those commands are invalid

atlas schema inspect -u "mysql://user:pass@localhost:3306/dbname" --exclude=dbname
atlas schema inspect -u "mysql://user:pass@localhost:3306/dbname" --exclude=dbname.*
atlas schema inspect -u "mysql://user:pass@localhost:3306/dbname" --exclude=dbname.table1

Need to update to this:

atlas schema inspect -u "mysql://user:pass@localhost:3306/dbname" --exclude=*
atlas schema inspect -u "mysql://user:pass@localhost:3306/dbname" --exclude=table1

For connection to realm, the exclude flag doesn't affect by this PR. So the bellow command still working fine.

atlas schema inspect -u "mysql://user:pass@localhost:3306" --exclude=dbname

[giautm]

I will wait for @a8m stamp.

[a8m]

Looks good, but see my only comment there.