[vector_graphics] Initial import (#7941)

Imports https://github.com/dnfield/vector_graphics into this repository,
with history, and updates it to follow repository conventions:
- Adds missing licence headers.
- Removes analysis options and fixes resulting warnings.
- Updates min SDKs.
- Autoformats.
- Updates pubspecs to follow repo standard, including updating the
metadata
  to point to the Flutter repositories.
- Allows `xml` as a pinned dependency, and relaxes the pinning
requirement
  in the repo tools to allow an explicit, inclusive-endpoint range.
- Skips some unit tests on unsupported platforms.
- Adds repo metadata.
- Bumps versions and slightly relax version constraints to allow the new
  versions.

script/tool/lib/src/pubspec_check_command.dart

@@ -612,7 +612,8 @@ Please move them to dev_dependencies.
       if (constraint is VersionRange &&
           constraint.min != null &&
           constraint.max != null &&
-          constraint.min == constraint.max) {
+          constraint.includeMin &&
+          constraint.includeMax) {
         return true;
       }
     }

script/tool/test/pubspec_check_command_test.dart

@@ -1674,7 +1674,8 @@ ${_topicsSection()}
         );
       });
 
-      test('passes when a pinned dependency is on the pinned allow list',
+      test(
+          'passes when an exactly-pinned dependency is on the pinned allow list',
           () async {
         final RepositoryPackage package =
             createFakePackage('a_package', packagesDir);
@@ -1701,6 +1702,34 @@ ${_topicsSection()}
         );
       });
 
+      test(
+          'passes when an explicit-range-pinned dependency is on the pinned allow list',
+          () async {
+        final RepositoryPackage package =
+            createFakePackage('a_package', packagesDir);
+
+        package.pubspecFile.writeAsStringSync('''
+${_headerSection('a_package')}
+${_environmentSection()}
+${_dependenciesSection(<String>['allow_pinned: ">=1.0.0 <=1.3.1"'])}
+${_topicsSection()}
+''');
+
+        final List<String> output = await runCapturingPrint(runner, <String>[
+          'pubspec-check',
+          '--allow-pinned-dependencies',
+          'allow_pinned'
+        ]);
+
+        expect(
+          output,
+          containsAllInOrder(<Matcher>[
+            contains('Running for a_package...'),
+            contains('No issues found!'),
+          ]),
+        );
+      });
+
       test('fails when an allowed-when-pinned dependency is unpinned',
           () async {
         final RepositoryPackage package =