feat: enhanced details in agent query and read_state errors

[krpeacock]

Description

extends the work done for call errors to query and read_state.
Additionally:

• fixes the thrown errors to use the same extended message as the logs
• exports errors and ObservableLog into the library so they can be used externally for testing

How Has This Been Tested?

more tests

Checklist:

• My changes follow the guidelines in CONTRIBUTING.md.
• The title of this PR complies with Conventional Commits.
• I have edited the CHANGELOG accordingly.
• I have made corresponding changes to the documentation.

[github-actions]

size-limit report 📦

Path	Size
@dfinity/agent	72.77 KB (+0.11% 🔺)
@dfinity/candid	11.65 KB (0%)
@dfinity/principal	4.16 KB (0%)
@dfinity/auth-client	50.25 KB (+0.05% 🔺)
@dfinity/assets	68.03 KB (+0.06% 🔺)
@dfinity/identity	47.88 KB (-0.08% 🔽)
@dfinity/identity-secp256k1	107.1 KB (+0.4% 🔺)