raise custom exception for pipeline errors

[fjlanasa]

Pull Request Description

Adds new exception class PipelineError to be raised for errors encountered when applying pipelines. The first implementation will be for raising an error in _transform_features when input data types are different from the input types the pipeline was fitted on.

---

After creating the pull request: in order to pass the release_notes_updated check you will need to update the "Future Release" section of docs/source/release_notes.rst to include this pull request by adding :pr:123.

[codecov]

Codecov Report

Merging #3497 (d509b9e) into main (483ed9a) will increase coverage by 0.1%.
The diff coverage is 100.0%.

@@           Coverage Diff           @@
##            main   #3497     +/-   ##
=======================================
+ Coverage   99.7%   99.7%   +0.1%     
=======================================
  Files        336     336             
  Lines      33400   33420     +20     
=======================================
+ Hits       33274   33294     +20     
  Misses       126     126             

Impacted Files	Coverage Δ
evalml/exceptions/__init__.py	100.0% <ø> (ø)
evalml/exceptions/exceptions.py	100.0% <100.0%> (ø)
evalml/pipelines/component_graph.py	99.8% <100.0%> (ø)
...valml/tests/pipeline_tests/test_component_graph.py	99.9% <100.0%> (+0.1%)	⬆️
evalml/tests/pipeline_tests/test_pipelines.py	99.8% <100.0%> (+0.1%)	⬆️

---

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 483ed9a...d509b9e. Read the comment docs.

[freddyaboulton]

Thank you @fjlanasa !

[chukarsten]

Just a small nit about docstrings, but looks good, thank you!