redis cache key deprecation

[V-nguard]

Post-merge checklist:

The master branch is auto-deployed to dash.plotly.com. Once you have merged your PR, wait 5-10 minutes and check dash.plotly.com to verify that your changes have been made.

• [x ] I understand

---

According to https://flask-caching.readthedocs.io/en/latest/index.html#rediscache,

I don't know if there are other instances where redis caches were shown using the deprecated string.

[alexcjohnson]

Thanks @JackyJang99 - it looks like there are several more places we need 'redis' -> 'RedisCache', also some 'filesystem' -> 'FileSystemCache'

> ag CACHE_TYPE
dash_docs/chapters/sharing_data/index.py
402:            'CACHE_TYPE': 'redis',

dash_docs/chapters/sharing_data/examples/Example4.R
17:#   'CACHE_TYPE': 'redis',
20:#   'CACHE_TYPE': 'filesystem',

dash_docs/chapters/sharing_data/examples/sharing_state_filesystem_sessions.py
20:    'CACHE_TYPE': 'redis',
23:    'CACHE_TYPE': 'filesystem',

dash_docs/chapters/sharing_data/examples/Example3.R
16:#   'CACHE_TYPE': 'redis',

dash_docs/chapters/performance/examples/performance_flask_caching.py
15:    'CACHE_TYPE': 'redis',

dash_docs/chapters/performance/examples/performance_flask_caching_dataset.py
15:    'CACHE_TYPE': 'filesystem',

FYI @plotly/services