fix(resource filters): add missing resource filters

[MrCloudSec]

Description

Add missing resource filters to Neptune, DocDB and ElastiCache.

License

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[jfagoagas]

Thanks @sergargar !!

[codecov]

Codecov Report

Merging #2951 (9dba760) into master (a46d7b2) will increase coverage by 0.00%.
Report is 2 commits behind head on master.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #2951   +/-   ##
=======================================
  Coverage   86.27%   86.27%           
=======================================
  Files         559      559           
  Lines       17902    17908    +6     
=======================================
+ Hits        15445    15451    +6     
  Misses       2457     2457           

Files	Coverage Δ
...ders/aws/services/documentdb/documentdb_service.py	86.95% <100.00%> (+0.59%)	⬆️
...rs/aws/services/elasticache/elasticache_service.py	81.81% <100.00%> (+0.68%)	⬆️
.../providers/aws/services/neptune/neptune_service.py	82.45% <100.00%> (+0.63%)	⬆️

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