Feature: add datetime to rules context (#484)

This PR adds date information to rules context allowing to condition a
profile deployment based on current year, month or day.

In the following example, the profile is installed only if QDT runs on a
Linux operating system and if the current year >= 2023:

```json
{
  "$schema": "https://raw.githubusercontent.com/Guts/qgis-deployment-cli/main/docs/schemas/profile/qgis_profile.json",
  "name": "QDT Only Linux",
  "folder_name": "qdt_only_linux",
  "description": "Demonstrating a QDT profile that's deployed only on Linux.",
  "author": "Julien Moura",
  "email": "infos+qdt@oslandia.com",
  "qgisMinimumVersion": "3.34.0",
  "qgisMaximumVersion": "3.99.10",
  "version": "1.0.0",
  "rules": [
    {
      "name": "Environment",
      "description": "Profile is configured to run only on Linux.",
      "conditions": {
        "all": [
          {
            "path": "$.environment.operating_system_code",
            "value": "linux",
            "operator": "equal"
          },
          {
            "path": "$.date.current_year",
            "value": 2023,
            "operator": "greater_than_inclusive"
          }
        ]
      }
    }
  ]
}
```


Depends on #481

examples/profiles/only_linux/profile.json

@@ -18,6 +18,11 @@
             "path": "$.environment.operating_system_code",
             "value": "linux",
             "operator": "equal"
+          },
+          {
+            "path": "$.date.current_year",
+            "value": 2023,
+            "operator": "greater_than_inclusive"
           }
         ]
       }

qgis_deployment_toolbelt/jobs/job_profiles_synchronizer.py

@@ -24,7 +24,10 @@
 # package
 from qgis_deployment_toolbelt.jobs.generic_job import GenericJob
 from qgis_deployment_toolbelt.profiles.qdt_profile import QdtProfile
-from qgis_deployment_toolbelt.utils.computer_environment import environment_dict
+from qgis_deployment_toolbelt.utils.computer_environment import (
+    date_dict,
+    environment_dict,
+)
 
 # #############################################################################
 # ########## Globals ###############
@@ -129,7 +132,7 @@ def filter_profiles_on_rules(
         li_profiles_matched = []
         li_profiles_unmatched = []
 
-        context_object = {"environment": environment_dict()}
+        context_object = {"date": date_dict(), "environment": environment_dict()}
         for profile in li_downloaded_profiles:
             if profile.rules is None:
                 logger.debug(f"No rules to apply to {profile.name}")

qgis_deployment_toolbelt/utils/computer_environment.py

@@ -11,9 +11,11 @@
 # ########## Libraries #############
 # ##################################
 
-# Standard library
 import logging
 import platform
+
+# Standard library
+from datetime import date
 from sys import platform as opersys
 
 # #############################################################################
@@ -29,6 +31,22 @@
 # ##################################
 
 
+def date_dict() -> dict:
+    """Returns a context dictionary with date informations that can be used in QDT
+    various places: rules...
+
+    Returns:
+        dict: dict with current date informations
+    """
+    today = date.today()
+    return {
+        "current_day": today.day,
+        "current_weekday": today.weekday(),  # monday = 0, sunday = 6
+        "current_month": today.month,
+        "current_year": today.year,
+    }
+
+
 def environment_dict() -> dict:
     """Returns a dictionary containing some environment information (computer, network,
         platform) that can be used in QDT various places: rules...