String type in the generated model class from lb4 discover not correct

[dhmlau]

Related to #2953

It seems like some of the items mentioned in #2953 wasn't fixed completely.

Runs the lb4 discover command and the generated code isn't exactly what we're looking for.

Steps to reproduce

1. Create a very simple table, e.g.

  Table "public.customer"
  Column  | Type | Collation | Nullable | Default 
----------+------+-----------+----------+---------
 custid   | text |           | not null | 
 custname | text |           |          | 

This is my command on postgres:

CREATE TABLE customer (custid text PRIMARY KEY, custname text);

2. Scaffold an app and create a datasource that connects to a database

3. Run:

npm run build
npm run migrate

Current Behavior

@property({
    type: String,
    required: true,
    id: 1,
    postgresql: {"columnName":"custid","dataType":"text","dataLength":null,"dataPrecision":null,"dataScale":null,"nullable":"NO"},
  })
  custid: String;

Expected Behavior

@property({
    type: string, <----- problem 1: lower case "string"
    required: true,
    id: 1,
    postgresql: {"columnName":"custid","dataType":"text","dataLength":null,"dataPrecision":null,"dataScale":null,"nullable":"NO"}, <--- problem 2: ideally it is formatted properly
  })
  custid: String;  <---- problem 3: lower case "string" 

See details in #2953 (comment)

Acceptance Criteria

There are more details in #3711 from @bajtos.

• inside @property, change the type to be string instead of String (listed as problem 1 above) --> see fix(cli): emit correct property definitions for built-in types in discovered models #4143
• as the type of the property, change the type to be string instead of String (listed as problem 3 above) --> see fix(cli): emit correct property definitions for built-in types in discovered models #4143
• Stretch goal: in the connector specific json inside @property, represent it as a TypeScript object --> see Use stringifyObject instead of JSON.stringify for connector metadata #4180

[bajtos]

See also #3711 that describes another aspect of this problem, one related to controllers & repositories.

[emonddr]

Double-check for other types as well.

[jannyHou]

My finding so far:

The model discover generator calls discoverSingleModel to get model definitions, and the schema returned from this function has primitive data type as camel case like String, instead of all lower case string