feat/add_deriv_positions_example

[aarmoa]

• Added example for liquidable positions request
• Removed sentry nodes from the valid network configs

[codecov[bot]]

Codecov Report

All modified lines are covered by tests :white_check_mark:

Comparison is base (0b3b17b) 56.28% compared to head (87b0af7) 56.50%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## dev #255 +/- ## ========================================== + Coverage 56.28% 56.50% +0.22% ========================================== Files 17 17 Lines 2038 2030 -8 Branches 241 240 -1 ========================================== Hits 1147 1147 Misses 855 855 + Partials 36 28 -8 ``` | [Files](https://app.codecov.io/gh/InjectiveLabs/sdk-python/pull/255?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=InjectiveLabs) | Coverage Δ | | |---|---|---| | [pyinjective/core/network.py](https://app.codecov.io/gh/InjectiveLabs/sdk-python/pull/255?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=InjectiveLabs#diff-cHlpbmplY3RpdmUvY29yZS9uZXR3b3JrLnB5) | `40.64% <ø> (+1.66%)` | :arrow_up: | ... and [1 file with indirect coverage changes](https://app.codecov.io/gh/InjectiveLabs/sdk-python/pull/255/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=InjectiveLabs)

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.