RegexpRule improvements and optimisation

[jclaveau]

• Convert PCRE to ElasticSearch regexps
• If a value of an equal rule doesn't match a pattern on the same field, we are in an invalid branch
• Finish the converstion between php PCRE and MariaDb PCRE

Related:

• How to check regex is valid or not?  elastic/elasticsearch-php#367
• https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-regexp-query.html