feat(Series) - Added items() method

[mobley-trent]

• Sub task of Add missing methods to Series #1259
• Tests added / passed
• Passes pre-commit run --all-files

[GPUtester]

Can one of the admins verify this patch?

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[github-actions]

Unit Test Results

See test report for an extended history of previous test failures. This is useful for diagnosing flaky tests.

     15 files  ± 0       15 suites  ±0   3h 17m 13s ⏱️ + 1m 44s
 13 032 tests + 1   12 100 ✅  - 1     931 💤 + 1  1 ❌ +1 
161 164 runs  +12  144 627 ✅  - 5  16 536 💤 +16  1 ❌ +1 

For more details on these failures, see this check.

Results for commit 557b691. ± Comparison against base commit ba5f3bc.

This pull request removes 2 and adds 3 tests. Note that renamed tests count towards both.

dask.tests.test_tokenize ‑ test_tokenize_local_classes_from_different_contexts
dask.tests.test_tokenize ‑ test_tokenize_local_instances_from_different_contexts

dask.dataframe.tests.test_dataframe ‑ test_items
dask.tests.test_tokenize ‑ test_tokenize_local_classes_from_different_contexts[False]
dask.tests.test_tokenize ‑ test_tokenize_local_classes_from_different_contexts[True]

This pull request removes 1 skipped test and adds 2 skipped tests. Note that renamed tests count towards both.

dask.tests.test_tokenize ‑ test_tokenize_local_instances_from_different_contexts

dask.tests.test_tokenize ‑ test_tokenize_local_classes_from_different_contexts[False]
dask.tests.test_tokenize ‑ test_tokenize_local_classes_from_different_contexts[True]