Review regex pattern for member_id and related collections

[glevava]

CMIP6 member_id collection allows only one digit in the regex pattern :

pyessv-archive/wcrp/MANIFEST

Line 1595 in 2621670

"term_regex": "r[0-9]i[0-9]p[0-9]f[0-9]",

The pattern has to allows more than one digit for each "realization parameter" with such kind of regex:
r[0-9]+i[0-9]+p[0-9]+f[0-9]+

This also should be modified for other supported projects (e.g. cmip5, etc.)

[glevava]

Partly solved in PR #4
Note that member IDs including sub_experiment_id will be still invalid. Need modification.