fix(cat-gateway): Fix native asset indexing to be more flexible

[apskhem]

Description

• Renamed the schema.
• Renamed the response object.
• Renamed the database mapping object.
• Fixed asset map to handle list of txos.

Related Issue(s)

Closes #1121

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• My code follows the style guidelines of this project
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• I have made corresponding changes to the documentation
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• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
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[github-actions]

✅ Test Report | ${\color{lightgreen}Pass: 291/291}$ | ${\color{red}Fail: 0/291}$ |

[github-actions]

✅ Test Report | ${\color{lightgreen}Pass: 320/320}$ | ${\color{red}Fail: 0/320}$ |

[github-actions]

✅ Test Report | ${\color{lightgreen}Pass: 320/320}$ | ${\color{red}Fail: 0/320}$ |

[stevenj]

See comments, these need to be corrected and then I will conduct another review.

[github-actions]

✅ Test Report | ${\color{lightgreen}Pass: 291/291}$ | ${\color{red}Fail: 0/291}$ |

[github-actions]

✅ Test Report | ${\color{lightgreen}Pass: 320/320}$ | ${\color{red}Fail: 0/320}$ |

[github-actions]

✅ Test Report | ${\color{lightgreen}Pass: 320/320}$ | ${\color{red}Fail: 0/320}$ |

[github-actions]

✅ Test Report | ${\color{lightgreen}Pass: 320/320}$ | ${\color{red}Fail: 0/320}$ |

[Mr-Leshiy]

From the original issue it is also telling to the change the asset value type to i128, which I dont see in this PR.
Is it really needed, or its something we dont want to do ?

[Mr-Leshiy]

Not quite get it this change.
Could you elaborate what we are doing here actually ?