Alter Postgres.php methods to return status + sql sentence

[ffflabs]

Instead of returning just the status of the executed query, the user should be presented with
a message containing the executed sentence.

An example of this can be seen in Postgres::alterColumn

In ColPropertyController::doAlter, this is the actual behavior.

Before:

column altered

After

ALTER COLUMN "my_column" TYPE bigint
column altered

It should be replicated for the rest of the database executed sentences.