Test: Add Unit & Widget Tests for saved_pages.dart

[GitMasterJatin]

What kind of change does this PR introduce?

• Added tests for saved_pages.dart.

Issue Number:

• Fixes Add unit & widget tests for saved_pages.dart #147

Summary

• Added tests to increase code coverage.

Screenshots

Does this PR introduce a breaking change?

• No

Other information

• Added mockito and build_runner package to write tests easily.

Have you read the contributing guide , README.md , code of conduct?

• Yes

[github-actions]

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[github-actions]

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[may-tas]

Please upload a screenshot showing that all tests are passing. You can use the VSCode extension to run the tests and take the picture.

[GitMasterJatin]

@may-tas done, see the description.

[may-tas]

@GitMasterJatin LGTM, merging.
Also the hacktoberfest is ending soon, hurry with your PRs or any new issues.