write.configs.ed should error if revision not specified

[infotroph]

I understand the logic of this bit, and I know you didn't add the line @Aariq, but I wonder if it would be better for the code to throw an error if the revision isn't specified. In general we're trying to reduce/isolate the dependency of pecan modules and functions on the database -- by fixing this one error-checking line we're making users of the ED2 module install the database.

Originally posted by @mdietze in #3135 (comment)

☝️ In reference to the following line of code in models/ed/write_configs.ed.R:

 model <- PEcAn.DB::db.query(paste("SELECT * FROM models WHERE id =", settings$model$id), params = settings$database$bety)