[tharropoulos]

• add SynonymSetItems and SynonymSetItem so synonym_sets[name].items can list, retrieve, upsert and delete single items, as the synonym docs in docs(30.2): fix broken code examples on the synonyms page typesense-website#524 do
• URL-encode both the set name and the item id in the item paths
• add AnalyticsRules#upsert(name, params), which v4 had on analytics.rules until v5 moved it to analytics_v1 (used by docs(30.2): fix broken code examples on the analytics-query-suggestions page typesense-website#519)
• rename AnalyticsRule#update to #upsert and keep update as an alias, since the PUT creates the rule when it's missing
• pass query params through AnalyticsRules#retrieve so retrieve(rule_tag: 'homepage') filters by tag (server v30.0+)
• add integration specs against Typesense 30.2, with spaces in names to catch missing encoding