0.5.8

Container: prevent scientific notation, cleanup lua code

Due to this issue: https://github.com/redis/redis/issues/7520
Big numbers cause cjson to prefer the scientific notation, which results
in a parse error on the collector side.

Code cleanup has been performed in order to homogenize result casting
from different lua scripts. Some redundant pieces of lua code have also
been removed, which should increase performance.

Finally, reported _bytes values have been obsoleted, as they can cause
issues when used in prometheus queries