feat: Private Groups + Load-Templates

Private Groups enabled based on the following assumptions:

* There is only one private group.
* The companies added to the private group is able to find private loads in the directory.
* The companies added to the private group is able to find private companies in the directory.
* The driver requires a new endpoint to read load resources no matter the privacy rules (as long as they are added to the load as driver).
* The private group can be updated by anyone within the company.
* The privacy is enabled on the company information by enabling `privacy=true`.
* The privacy is enabled on the loads information by enabling `privacy=true`.
* When looking for loads/companies by default the search is with `privacy=false` which returns public elements. When `privacy=true`is given, the results are limited to private elements only (not including public elements).

Load-Templates enabled based on the following assumptions:

* Anyone can CRUD the templates, there is no find feature (for now). It is assumed that the number of templates is limited.

v1/src/lib/Models/loads.model.js

@@ -90,7 +90,9 @@ const schema = new Schema({
 
     payment_term: { type: String },
     terms_and_conditions: { type: String },
-    createdAt: { type : Date, required : true, default : () => { return Date.now(); } }
+    createdAt: { type : Date, required : true, default : () => { return Date.now(); } },
+
+    privacy: { type: Boolean, default: false }, /// Disables visibility on the directory, only enabled for private groups. 
 });
 
 module.exports = mongoose.model( "loads", schema );