feat(apiconnect): add OAS extension typedefs

[achrinza]

Timebox: 1 week

Todo:

• [x] Separate "Execute" on a per-gateway type basis
• [x] Separate "Execute" on a per-version basis
• [x] Update circular references to "Execute" to accept a generic to allow passthrough of the Execute version.
• [ ] Allow explicit declaration of "minimum policy version" for execute, assembly, and APIConnectOASObjects.OpenAPIObject via generics. (Partially done, remaining OpenAPIObject)

Future work:

• Write tsdoc
• Write typedef tests
• Allow importing of individual policy by their versions.
• Create a helper validator functions
• Allow blocking of OAS spec from being served by API gateway
• Allow filtering of OAS spec to exclude x-ibm-configuration from being served

Things to fix:

• [x] Identify where WebSocketUpgrade is supposed to be located
• Apply "X-IBM-Languages" to all supported OpenAPI 3.0 Objects.

Signed-off-by: Rifa Achrinza [email protected]

Checklist

• [x] DCO (Developer Certificate of Origin) signed in all commits
• [x] npm test passes on your machine
• New tests added or existing tests modified to cover all changes
• [x] Code conforms with the style guide
• [x] API Documentation in code was updated
• Documentation in /docs/site was updated
• Affected artifact templates in packages/cli were updated
• Affected example projects in examples/* were updated

👉 Check out how to submit a PR 👈

[coveralls]

Pull Request Test Coverage Report for Build 1550131111

• 11 of 11 (100.0%) changed or added relevant lines in 4 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 76.04%

---

Totals
Change from base Build 1533140642:	0%
Covered Lines:	16931
Relevant Lines:	17918

---

💛 - Coveralls