Improve stack traces

[mrlubos]

Example stack trace

Reference not found: #/components/schemas/validation-error
Error: Reference not found: #/components/schemas/validation-error
    at resolveRef (/@hey-api/openapi-ts/packages/openapi-ts/dist/index.cjs:3145:13)
    at IRContext.resolveRef (/@hey-api/openapi-ts/packages/openapi-ts/dist/index.cjs:3245:12)
    at parseRef3 (/@hey-api/openapi-ts/packages/openapi-ts/dist/index.cjs:7963:31)
    at schemaToIrSchema3 (/@hey-api/openapi-ts/packages/openapi-ts/dist/index.cjs:8152:12)
    at operationToIrOperation3 (/@hey-api/openapi-ts/packages/openapi-ts/dist/index.cjs:8409:17)
    at parseOperation3 (/@hey-api/openapi-ts/packages/openapi-ts/dist/index.cjs:8470:38)
    at parseV3_1_X (/@hey-api/openapi-ts/packages/openapi-ts/dist/index.cjs:8762:7)
    at parseOpenApiSpec (/@hey-api/openapi-ts/packages/openapi-ts/dist/index.cjs:11872:7)
    at createClient (/@hey-api/openapi-ts/packages/openapi-ts/dist/index.cjs:12189:17)
    at async Promise.all (index 0)
    at async createClient3 (/@hey-api/openapi-ts/packages/openapi-ts/dist/index.cjs:24463:21)
    at async start (/@hey-api/openapi-ts/packages/openapi-ts/bin/index.cjs:131:21)

Ideally we'd have context about each step where it matters: which operation was being processed, which schema was being processed, which field was being processed, etc.