refactor(amplifier): standardizes contract config read/write between chain specific and global contracts

[eguajardo]

• differentiates between contractConfig (e.g. config.axelar.contracts.Gateway.avalanche) and contractBaseConfig (e.g. config.axelar.contracts.Gateway), both are equivalent for global contracts
• adds lastUploadedCodeId attribute to contractBaseConfig
• moves codeId to contractConfig
• upload (also scripts with --fetchCodeId option) will update lastUploadedCodeId instead of codeId
• instantiation and migration will set codeId in contractConfig
• scripts have 3 ways to get the codeId for instantiation/migration (previously set contractConfig.codeId will be ignored), in order of priority:
  1. take it from argument if --codeId was set
  2. if --fetchCodeId flag was set, it retrieves the code Id from the network by comparing the code hash stored from a governance proposal
  3. copies contractBaseConfig.lastUploadedCodeId which was previously set during upload

https://axelarnetwork.atlassian.net/browse/AXE-5189