fix: update WstETHAdapter and tests to set ETH base asset price to 1

[matias-gonz]

• Changed the base asset price for ETH in WstETHAdapter from 0 to 1 to ensure accurate pricing.
• Updated related tests to verify that the ETH price is now correctly set to 1 instead of 0.
• Adjusted documentation to clarify the base asset pricing behavior.

[Copilot]

Pull Request Overview

This PR updates the WstETHAdapter to set the ETH base asset price to 1 instead of 0, aligning with accurate pricing conventions. The change affects both the adapter implementation and the oracle helper's encoding logic.

Key changes:

• Modified WstETHAdapter to set ETH price to 1 instead of 0
• Added logic in encode_asset_prices() to normalize base asset price to 0 before encoding
• Updated all related test assertions to verify ETH price is now 1

Reviewed Changes

Copilot reviewed 4 out of 5 changed files in this pull request and generated 1 comment.

File	Description
src/tq_oracle/adapters/price_adapters/wsteth.py	Changed ETH base asset price from 0 to 1 in fetch_prices method and updated documentation
src/tq_oracle/processors/oracle_helper.py	Added logic to overwrite base asset price to 0 during encoding, with updated documentation
tests/adapters/price_adapters/test_wsteth.py	Updated test assertions to expect ETH price of 1 instead of 0
tests/processors/test_oracle_helper.py	Added new test to verify base asset price is overwritten to 0 during encoding

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