Introduce chain connector plugin

[shuse2]

Description

Introduce new plugin to support interoperability.
This plugin should be used by relayer node to automatically submit the cross chain update transaction.

Motivation

To facilitate cross chain communication, relayer node is required. To be a relayer node, it needs to maintain and aggregate offchain information to generate cross chain update transaction.

Tasks

• Bootstrap Chain connector plugin #7217
• Setup configuration for chain connector plugin #7218
• Expose endpoints from consensus to support CCU creation #7326
• Implement functions used in creation of CCUs #7219
• Setup all the stores required to store headers and aggregateCommits #7220
• Create new block handler for chain connector plugin #7221
• Implement cleanup function for chain connector plugin #7222
• Implement chain connector plugin Endpoint #7223
• Implement createCCU function for chain connector plugin #7224
• Collect CCMs from the events for Chain connector plugin #7378
• Store cross chain messages in a separate store to be fetched by height #7569
• Add method to sign a CCU transaction and send it to the other chain #7457
• Add CCU transaction creation and posting on sidechain from mainchain #7439
• Use max CCU size to collect CCM #7458
• Update CcmSendSuccessEvent to have CCM in the data #7836
• Fix build error on chain connector after development branch merge #7835
• Create handler for deleteBlock event for chain connector #7884
• Refactor chain connector DB to store both mainchain and sidechain #7888
• Remove CCM based frequency from chain connector #7889
• Update the flow of new block handler in chain connector plugin #7890