feat: enhance Docker image name validation and update dependencies

[yazdanbhd]

Issue: #41

Description:
Replaced custom regex-based Docker image validation with the official kubectl approach using github.com/distribution/reference package.

Changes:

• Added github.com/distribution/reference dependency
• Updated DockerImageValidator function to use reference.ReferenceRegexp.MatchString()
• Removed custom regex pattern and unused imports
• Updated test cases to match new validation behavior
• Fixed CLI error handling for validation failures

Files modified:

• internal/docker/function.go
• internal/docker/fucntion_test.go
• cmd/cli/fastdocker.go
• cmd/cli/root.go
• go.mod (dependency added)

Testing:

• All tests pass
• CLI validation working correctly
• Build successful