Added more tests to increase code coverage

[V3lop5]

This PR ...

added more tests to increase code coverage.

---

Checklist

Checklist for Contributors

• Unit tests provided?
  Unit tests are needed for new features or to reproduce the bug solved by this PR.
• Documentation updated?
• Unit tests successful
• Code smells (flake8) checked

Checklist for Reviewers

• Read PR description
• Check linked issue
• Check CI/CD (build, automated tests, linting, preview build)
• Check documentation changes
• Add labels to PR

[codecov-commenter]

Codecov Report

Merging #125 (cfb7b76) into main (03c0629) will increase coverage by 5.59%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main     #125      +/-   ##
==========================================
+ Coverage   79.42%   85.01%   +5.59%     
==========================================
  Files         104      104              
  Lines        2522     2522              
==========================================
+ Hits         2003     2144     +141     
+ Misses        519      378     -141     

Flag	Coverage Δ
pytest	85.01% <ø> (+5.59%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
ensysmod/core/file_upload.py	87.09% <0.00%> (+0.80%)	⬆️
ensysmod/crud/base_depends_component.py	88.46% <0.00%> (+3.84%)	⬆️
ensysmod/crud/base_depends_dataset.py	100.00% <0.00%> (+12.50%)	⬆️
ensysmod/api/endpoints/datasets.py	86.36% <0.00%> (+13.63%)	⬆️
ensysmod/crud/energy_transmission_distance.py	85.71% <0.00%> (+14.28%)	⬆️
ensysmod/crud/base_depends_timeseries.py	85.45% <0.00%> (+27.27%)	⬆️
ensysmod/utils/encoders.py	92.20% <0.00%> (+70.12%)	⬆️
ensysmod/core/file_download.py	100.00% <0.00%> (+78.26%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 03c0629...cfb7b76. Read the comment docs.

[github-actions]

Unit Test Results

    1 files  ±  0      1 suites  ±0   1m 55s ⏱️ + 1m 6s
417 tests +17  401 ✔️ +17  16 💤 ±0  0 ❌ ±0 

Results for commit cfb7b76. ± Comparison against base commit 03c0629.