cfmigrations runs hundreds of duplicate SQL queries on app init

[michaelborn]

Running migrationService.hasMigrationsToRun( "up" ) to check for migrations to run causes cfmigrations to run a SQL query for every migration cfc in the migrations directory. So if you have a large app with hundreds or thousands of migrations, cfmigrations will run SELECT name from cfmigrations hundreds or thousands of times!

To fix this, we should cache the query results in the variables scope:

https://github.com/coldbox-modules/cfmigrations/blob/v2.0.10/models/MigrationService.cfc#L311-L318

var migrations = queryExecute(
    "
        SELECT name
        FROM #getMigrationsTable()#
    ",
    {},
    { datasource : getDatasource() }
);