Tests for context.go file

[coolwednesday]

Adding test functions for context.go file

• Goal is to increase overall coverage of the gofr package.
• I have added test for functions, not covered before in context.go file.

Checklist:

• [x] I have formatted my code using goimport and golangci-lint.
• [x] All new code is covered by unit tests.
• [x] This PR does not decrease the overall code coverage.
• [x] I have reviewed the code comments and documentation for clarity.