Implement implicit_context for helper functions.

[saxena-anurag]

Fixes #3645

Description

This PR contains changes to support implicit context for helper functions. This required the following changes:

1. Update native code generation to also pass ctx to all the helper functions as 6th argument. Note that ubpf already does the same for JIT and interpret paths (though there was a bug in ubpf which was recently fixed, and is now included in eBPF).
2. Changed logic to resolve helper functions to now also get whether the helper function requires implicit context.
3. Checks in native module to ensure that an older native module (that does not support implicit context) does not get loaded if the extension requires implicit context for any of the helper functions used by the native module.
4. Updated the minor version to 0.18.0, to allow adding checks in native code.

Testing

Existing CICD. Also added new tests for implicit context.

Documentation

Updated documentation.

Installation

No.