Add cut-off dates

[andrew2net]

The need to add date filtering options to relaton-cli.

$ relaton fetch 'IEC 80000-6' --publication-date-before 2008
$ relaton fetch 'IEC 80000-6' --publication-date-after 2002
$ relaton fetch 'IEC 80000-6' --publication-date-before 2008-02-02 --publication-date-after 2002-01-01

@ronaldtse we need to pass these options to relaton-* gems and implement filtering by date in each flavor gem. Some gem don't have parsed ID parts yet. It will take time.
We can implement the functionality for IEC first, publish release, and add the functionality to other relaton flavor gems later. Or, we can publish release when then the functionality will be released in all relaton-* gems. What do you think?

metanorma/metanorma-standoc#773 (comment)

[andrew2net]

@ronaldtse with the relaton cache we need to check if there is cached document that matches given reference and has date between publication-date-after and publication-date-before. But documents have a list of different types of dates. Not every document has published date. Some flavor gems like relaton-iso returns all-parts documents without dates (dated documents are attached as relations). We need to decide which type of date we should use if we don't have published date. And what to do if we don't have date at all or we have all-parts document. Do you have any thoughts?

[andrew2net]

This issue depends on relaton/relaton-iec/issues/55