[SERVICES][HTTP][CONFIG] Implement per Service Specification for Services, Provide Clearer Errors to User when Outside of Spec

[fredteumer]

Objective

Provide per-service EVM Specification to PATH and return 4XX when improper methods are called.

Origin Document

Makes it easier for a user to determine if a given method is supported or not on EVM.

Goals

• Provide clear documentation to the user via an error (and corresponding error type) that a method is unsupported
• Improve configurability/optionality of PATH

Deliverables

• Implement per-service configuration for specification
• Implement a 4xx error when something that is not in that specification is invoked to the user with a clear error message

Non-goals / Non-deliverables

• Enhancements to non-EVM chains

General deliverables

• Comments: Add/update TODOs and comments alongside the source code so it is easier to follow.
• Testing: Add new tests (unit and/or E2E) to the test suite.
• Makefile: Add new targets to the Makefile to make the new functionality easier to use.
• Documentation: Update architectural or development READMEs; use mermaid diagrams where appropriate.

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Creator: @fredteumer