feat(jans-cedarling): add an example that runs profiling

[rmarinn]

Prepare

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Description

This PR adds an example that runs profiling while calling Cedarling::authorize then

1. writes the output to the stdout (hard for humans to read)
2. saves an SVG file at jans_cedarling/cedarling_profiling_flamegraph.svg (easier for humans to read)

Target issue

target issue: #10978

closes #10978

Implementation Details

Use this command to run the example:

cargo run --example profiling

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Test and Document the changes

• Static code analysis has been run locally and issues have been fixed
• Relevant unit and integration tests have been added/updated
• Relevant documentation has been updated if any (i.e. user guides, installation and configuration guides, technical design docs etc)

Please check the below before submitting your PR. The PR will not be merged if there are no commits that start with docs: to indicate documentation changes or if the below checklist is not selected.

• I confirm that there is no impact on the docs due to the code changes in this PR.

[duttarnab]

I think we should add a section in the README or docs explaining how the profiling data/graph can be used for optimizing the project further.

[rmarinn]

I think we should add a section in the README or docs explaining how the profiling data/graph can be used for optimizing the project further.

honestly, i think it's pretty explanatory... the longer the bars in the graph, the longer it takes to run. and the bars are labeled with the function names.