VO Cone Search validator noncritical warnings to depend on VO Table schema version

*This was astropy/astropy#4163*

According to http://docs.astropy.org/en/stable/io/votable/api_exceptions.html , some VO Table warnings only apply if VO Table schema version is such-and-such. To accommodate more accurate validation reporting, `astroquery.vo_conesearch.validator.conf.noncrit_warnings` configuration item needs to be changed to account for VO Table schema version (1.0, 1.1, 1.2, and 1.3).

**Proposed Solution**

Since using `dict` in configuration item is not an option, we can replace `noncrit_warnings` with `noncrit_warnings_[ver]` (e.g., `noncrit_warnings_v1d1`, `noncrit_warnings_v1d2`, and so forth). Each will have a list of noncritical warnings that is customized for that version. For example, VO Table schema version 1.1 will use `noncrit_warnings_v1d1`.

**Work Description**
- The configuration changes go into `astroquery/vo_conesearch/validator/__init__.py`
- Validation logic in `astroquery/vo_conesearch/validator/validate.py` needs to be updated accordingly
- Documentation and change log need updating
- Tests should work as-is, but some results might change
- Update Cone Search tutorial in Astropy tutorials

**Backward Compatibility**

Not backward compatible. I do not see a need for it, as I think I am the only person in the world who uses the validator.

**Priority**

Low.

Start with astroquery/vo_conesearch/validator/__init__.py and validate.py, then review the referenced VO Table warning behavior and existing validator tests. Update configuration and validation for VO Table versions 1.0–1.3, and confirm changed results. Done also requires updated documentation, changelog, and the Cone Search tutorial in Astropy tutorials.

Written by the indexing model from the issue text.