Update release-data JSON file format

This makes the format open for extension, such as adding release cycle level data (such as EOL dates).

Version data is still accessible by the version's name. While this repeats the version name, it's also much more convenient for users of those data.

A few other things have also been updated in the process:

- verbosity of the diff has been increased in update.py to make workflow summaries more readable,
- dates without timezone are now set to UTC by default (this was already supposed, so no impact expected here).

latest.py

@@ -22,8 +22,8 @@
 
 
 class ReleaseCycle:
-    def __init__(self, product_name: str, data: dict) -> None:
-        self.product_name = product_name
+    def __init__(self, product: "Product", data: dict) -> None:
+        self.product = product.name
         self.data = data
         self.name = data["releaseCycle"]
         self.matched = False
@@ -90,14 +90,14 @@ def __update_latest(self, version: str, date: datetime.date) -> None:
             self.updated = True
 
     def __str__(self) -> str:
-        return self.product_name + '#' + self.name
+        return self.product + '#' + self.name
 
 
 class Product:
     def __init__(self, name: str, product_dir: Path, versions_dir: Path) -> None:
         self.name = name
         self.product_path = product_dir / f"{name}.md"
-        self.versions_path = versions_dir / f"{name}.json"
+        self.release_data_path = versions_dir / f"{name}.json"
 
         with self.product_path.open() as product_file:
             # First read the frontmatter of the product file.
@@ -109,31 +109,32 @@ def __init__(self, name: str, product_dir: Path, versions_dir: Path) -> None:
             product_file.seek(0)
             _, self.content = frontmatter.parse(product_file.read())
 
-        with self.versions_path.open() as versions_file:
-            self.versions = json.loads(versions_file.read())
+        with self.release_data_path.open() as release_data_file:
+            self.release_data = json.loads(release_data_file.read())
 
-        self.releases = [ReleaseCycle(name, release) for release in self.data["releases"]]
+        self.releases = [ReleaseCycle(self, release) for release in self.data["releases"]]
         self.updated = False
         self.unmatched_versions = {}
 
     def check_latest(self) -> None:
         for release in self.releases:
             latest = release.latest()
-            if release.matched and latest not in self.versions:
-                logging.info(f"latest version {latest} for {release} not found in {self.versions_path}")
+            if release.matched and latest not in self.release_data["versions"]:
+                logging.info(f"latest version {latest} for {release} not found in {self.release_data_path}")
 
-    def process_version(self, version: str, date_str: str) -> None:
-        date = datetime.date.fromisoformat(date_str)
+    def process_version(self, version_data: dict) -> None:
+        name = version_data["name"]
+        date = datetime.date.fromisoformat(version_data["date"])
 
         version_matched = False
         for release in self.releases:
-            if release.includes(version):
+            if release.includes(name):
                 version_matched = True
-                release.update_with(version, date)
+                release.update_with(name, date)
                 self.updated = self.updated or release.updated
 
         if not version_matched:
-            self.unmatched_versions[version] = date
+            self.unmatched_versions[name] = date
 
     def write(self) -> None:
         with self.product_path.open("w") as product_file:
@@ -156,8 +157,8 @@ def update_product(name: str, product_dir: Path, releases_dir: Path, output: Git
         return
 
     product = Product(name, product_dir, releases_dir)
-    for version, date_str in product.versions.items():
-        product.process_version(version, date_str)
+    for version_data in product.release_data["versions"].values():
+        product.process_version(version_data)
     product.check_latest()
 
     if product.updated: