Hive Blockchain version bumped to 1.27.5

Proposed release notes to be used at tagged version:

This is a minor release: 1.27.5. It does not require a hardfork nor a hived node upgrade (although it is recommended). Upgraded nodes will require a full replay.

1. Hive/Blockchain features/improvements
   • Hardfork 28 changes (note: date in code is a placeholder HF28 date, likely to change in the future):
     • Multiple recurrent transfers for same sender/receiver pair: !870 (merged)
     • Tests and fix (enabled at HF28) related to bad vests/hive price rounding that lead to improper calculations at very early hardforks: !901 (merged)
   • Account history API improvements (defines an explicit operation filter for API calls): !898 (merged)
   • All condenser API methods return result sets using the JSON legacy form: !964 (merged)
   • proposal_pay_operation (virtual operation) uses less space (unneeded fields have been removed): !973 (merged)
   • Ability to specify some chain parameters in non-mainnet builds in order to simplify testing: !888 (merged)
   • Fix bugs related to fc logger (file appenders):
     • !934 (merged)
     • !946 (merged)
   • Fix random crash at hived exit: !990 (merged)
   • The auto-generated block_log.artifacts file has a new format and supports interruption and better consistency validation:
     • !949 (merged)
     • !974 (merged)
     • !983 (merged)
   • Improve validation of snapshot consistency (improved validation):
     • !913 (merged)
     • !919 (merged)
     • loading a snapshot automatically wipes any old shared memory file (previously the loading aborted with an error message): !969 (merged)
   • Resource constraint (RC) code moved closer to the chain code, slightly reducing memory footprint, making it more core-code compliant, and iteratively preparing for RC to be part of consensus in the future:
     • !917 (merged)
     • !951 (merged)
   • In order to speed up file IO, hived has a new dependency: uring library !968 (merged)
   • Code cleanup:
     • Removed legacy operation classes & related code: !923 (merged)
     • Removed support for unused automated actions: !938 (merged)
2. New beekeeper tool that safely holds customer keys and signs Hive transactions without a need to directly access private keys:
   • !902 (merged)
   • !929 (merged)
   • Beekeeper is directly accessible from JS environments (e.g. web browser): !976 (merged)
3. DevOps/CI improvements:
   • Common job definitions used across several Hive repos: !765 (merged)
   • Mirrornet conversion can be done automatically: !877 (merged)
4. Tests improvements:
   • Unified unit tests startup by sharing regular hived code inside Boost Unit Test framework: !948 (merged)
   • Shared tools/test code across HAF repo: !892 (merged)
   • Thorough tests specific to Account History API: !928 (merged)
   • Improved tests related to decline_voting_rights behavior
   • Dedicated test scenarios for verifying account recovery system !885 (merged)
   • Dedicated test scenarios for power up !911 (merged)
   • Dedicated test scenarios for limit order create: !927 (merged)