OpenAPI 3.x.y rules finalization

[char0n]

The scope of this issue is to double-check OpenAPI 3.x.y rules in language service, provide PRs for quick fixes and create issues for more complex issues.

List of identified issues and PRs:

• fix(ls): fix OpenAPI Link.requestBody field completion #2207
• OpenAPI 3.x.y - validation of runtime expression #2208
• OpenAPI 3.x.y - reuse documentation strings #2209
• OpenAPI 3.x.y - optimize usage of target spec #2210
• fix(ls): provide spec extension lint rule for Discriminator #2211
• feat(ls): provide OpenAPI 3.1.0 Example allowed fields link rule #2212
• OpenAPI 3.x.y - Link.operationId - completion should complete from all possible local Operations Objects #2213
• OpenAPI 3.x.y - Link.operationRef - completion should complete from all possible local Operations Objects #2214
• fix(ls): fix docs rule for OpenAPI 3.x.y Parameter #2215
• fix(ls): provide OpenAPI 3.1 Request Body allowed fields lint rule #2216
• feat(ls): provide OpenAPI 3.1 Response allowed fields link rule #2217
• feat(ls): provide OpenAPI 3.1 Responses docs rules #2218
• OpenAPI 3.1.0 - no errors on Petstore fixture #2219

[char0n]

I'll continue with this issue on Monday, I have another 12 items that can be transformed into issues but currently non of those items are closely related to OpenAPI 3.1.0.

[char0n]

Here is the list of issues discovered during OpenAPI 3/ AsyncAPI 2.5 implementations that only existed in my notes before.
Issues that I've created during the implementations are excluded from this list (excluded issues count is about the same as this one).

• SwaggerEditor@next: dependabot updates react-scripts swagger-editor#3596
• SwaggerEditor@next: double scrollbar in validation pane swagger-editor#3625
• SwaggerEditor@next: support for local reference indirections swagger-editor#3626
• SwaggerEditor@next: use more appropriate fixtures swagger-editor#3627
• SwaggerEditor@next: unescaped autocompletion of references swagger-editor#3628
• SwaggerEditor@next: incorrect documentation links in on-hover documentation swagger-editor#3638
• SwaggerEditor@next - expose VSCode providers to the plugin system swagger-editor#3639
• apidom-ls: add support for conditional documentation display #2266
• OpenAPI 3.0.x parser adapters - remove ability to recognize RC versions of the spec #2265
• OpenAPI 3.x.y - all the required fields validation needs to take account of $ref field #2264
• AsyncAPI 2.x - OAuth Flow required fields validation #2263
• apidom-ls: AsyncAPI 2.x Reference Object optimization #2261
• fix(ibmmq): make topic field required asyncapi/bindings#169

@frantuma - this smaller list contains issues you should probably:

• SwaggerEditor@next: support for local reference indirections swagger-editor#3626
• SwaggerEditor@next: unescaped autocompletion of references swagger-editor#3628
• SwaggerEditor@next: incorrect documentation links in on-hover documentation swagger-editor#3638
• apidom-ls: add support for conditional documentation display #2266

Note: every bug/issue I found and could be fixed quicly, I've addressed with a PR without an issue