build!: release v3.0.0-rc1

[jaybxyz]

Description

This PR is the first release candidate for v3.0.0.

Tasks

• [x] apply semantic versioning on all files from squad/v2/ to sqaud/v3/
• [x] update swagger version to 3.0.0
• [x] update related docs

References

• https://github.com/cosmosquad-labs/squad/pull/322

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• [ ] Appropriate labels applied
• [ ] Targeted PR against correct branch
• [ ] Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• [ ] Code follows the module structure standards.
• [ ] Wrote unit and integration
• [ ] Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• [ ] Added relevant godoc comments.
• [ ] Re-reviewed Files changed in the Github PR explorer
• [ ] Review Codecov Report in the comment section below once CI passes