feat: update oracle skills and demo

[jrriehl]

Proposed changes

Simplifies oracle skills by removing the libp2p connection and defaulting to the fetchai ledger.

Types of changes

What types of changes does your code introduce to agents-aea? Put an x in the boxes that apply

• [ ] Bugfix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

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• [x] I have read the CONTRIBUTING doc
• [x] I am making a pull request against the develop branch (left side). Also you should start your branch off our develop.
• [x] Lint and unit tests pass locally with my changes and CI passes too
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] I have checked that code coverage does not decrease.
• [x] I have added necessary documentation (if appropriate)
• [x] Any dependent changes have been merged and published in downstream modules

[github-actions[bot]]

Visit the preview URL for this PR (updated for commit 7596c05):

https://fetch-docs-preview--pr2741-feat-oracle-skills-u-s08lyxmo.web.app

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[5A11]

@solarw please resolve the merge conflicts.

[codecov-commenter]

Codecov Report

Merging #2741 (3e328fb) into develop (5ae92cc) will decrease coverage by 0.00%. The diff coverage is n/a.

:exclamation: Current head 3e328fb differs from pull request most recent head c47d6ae. Consider uploading reports for the commit c47d6ae to get more accurate results

@@             Coverage Diff             @@
##           develop    #2741      +/-   ##
===========================================
- Coverage    97.96%   97.96%   -0.01%     
===========================================
  Files          522      522              
  Lines        36498    36498              
===========================================
- Hits         35757    35754       -3     
- Misses         741      744       +3     

Flag	Coverage Δ
unittests	97.96% <ø> (-0.01%)	:arrow_down:

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

Impacted Files	Coverage Δ
aea/connections/base.py	98.18% <0.00%> (-1.82%)	:arrow_down:

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[5A11]

@solarw Failure for test_simple_oracle.py. I think it is minor and just needs an update to a package number (0.17.0 to 0.17.1).