feat: added GtfsNetworkSchema

[qcdyx]

Summary:

Part 3 of #1640
Closes #1640

Expected behavior:
added a new GtfsNetworkSchema in code which represents the networks.txt.
https://docs.google.com/spreadsheets/d/1iyb8SCRxEXiK8-PHq0_Ut1_QUbeUEbQF6yZiA54WztU/edit#gid=1906649886

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• Run the unit tests with gradle test to make sure you didn't break anything
• Add or update any needed documentation to the repo
• Format the title like "feat: [new feature short description]". Title must follow the Conventional Commit Specification(https://www.conventionalcommits.org/en/v1.0.0/).
• Linked all relevant issues
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[github-actions]

This contribution does not follow the conventions set by the Google Java style guide. Please run the following command line at the root of the project to fix formatting errors: ./gradlew goJF.

[emmambd]

Route-based fares appears! LGTM on a QA side.

[github-actions]

✅ Rule acceptance tests passed.
New Errors: 0 out of 1481 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Errors: 0 out of 1481 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
New Warnings: 0 out of 1481 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Warnings: 0 out of 1481 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
0 out of 1481 sources (~0 %) are corrupted.
Commit: 19b685b
Download the full acceptance test report here (report will disappear after 90 days).
✅ Rule acceptance tests passed.

[github-actions]

✅ Rule acceptance tests passed.
New Errors: 0 out of 1481 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Errors: 0 out of 1481 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
New Warnings: 0 out of 1481 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Warnings: 0 out of 1481 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
0 out of 1481 sources (~0 %) are corrupted.
Commit: 9923f59
Download the full acceptance test report here (report will disappear after 90 days).
✅ Rule acceptance tests passed.