Schema properties are not updated if schema definition does not change

**Describe the bug**
The only available operation to update properties of a schema (`SchemaInfo`) is to use `createSchema()` method of `PulsarAdmin`. The problem with that is that it will not update the provided properties if schema definition does not change.

The only way the admin API provides to update the properties associated with an schema is to delete it first and then create it from scratch. This can be dangerous because if schema creation fails aftewards we will be left with an unreadable topic (missing schema) and also different consumers using different schema versions may also face issues (when we delete an schema all versions are deleted).

**To Reproduce**
```
PulsarAdmin client = createClient();
String topicUri = getTopicUri();

SchemaInfo info = client.schemas().getSchemaInfo(topicUri);

/*
* We add a new property
*/
info.getProperties().put("newProp", "newValue");

PostSchemaPayload sp = new PostSchemaPayload();
sp.setType(info.getType().toString());
sp.setSchema(info.getSchemaDefinition());
sp.setProperties(info.getProperties());

/*
* This should update schema properties
*/
client.schemas().createSchema(topicUri, sp);

/*
* This object does not contain "newProp"
*/
info = client.schemas().getSchemaInfo(topicUri);
```

**Expected behavior**
Method to create/update schema should update properties even if schema definition does not change.

**Screenshots**

**Desktop (please complete the following information):**
- Windows with Docker Desktop

**Additional context**