Add missing filters and providers

• Mentions are now parsed from the post metadata instead of parsing the entire body of comment
• Added Known exchanges filter and provider - onExchangeTransfer
• Added feed price-related filters and providers - onFeedPriceChange, onFeedPriceNoChange and provideFeedPriceData
• Added witness-related filters and providers - onWitnessMissedBlocks and provideWitnesses
• Added internal market operations filter and provider - onInternalMarketOperation
• Added alarms notifier based on Clive alarms system - onAlarm
• Optimized providers creation
• Exported all missing type declarations
• Minor fixes improving overall user experience when running bots