Potential dependency resolution issue with base64

[Farhad-Shabani]

Problem Statement

Encountered a dependency resolution issue while working on informalsystems/sovereign-ibc#67. The issue stems from the base64 dependency, as the compiler is unable to determine a proper version.

Proposal

Bringing base64 into the workspace and ensuring consistent versioning across all related crates. Additionally, considering loosening the version constraint to the minor level, allowing the compiler flexibility to select the appropriate version, especially in projects where different patch versions may be employed.

Version

=< 0.50.0