Allow all parameters in the cache config, and override them in specific usages

When setting the cache config, I'd like to set there default values (for TTL and namespace for example):

```py
caches.set_config({
'default': {
'cache': "aiocache.SimpleMemoryCache",
'namespace': 'my_namespace',
'ttl': 60,
},
})
```
From that point, all the usages of the `default` cache would use the namespace and ttl set, unless passed explicitly in decorators and calls:

```py
@cached(alias='default')
async def something_cached(self):
# This would cache with the default parameters defined in the config
return await do_stuff()

@cached(alias='default', namespace='another_namespace', ttl=3600)
async def something_else_cached(self):
# This would cache with the parameters defined in the decorator instead of the config
return await do_stuff()

# Same for these
caches.get('default').get('foo', default=False, namespace='bar_namespace')
caches.get('default').set('foo', True, namespace='bar_namespace', ttl=86400)
```