Add "helloworld" & "runtime" tests for newer .NET and Ballerina runtimes

Currently, we have "helloworld" tests for other langs and need some equivalency for newer runtime langs. of .NET and Ballerina. Here is what we have now for "helloworld":

```
./tests/src/integration/export/manifest_helloworld.yaml: runtime: nodejs:6
./tests/src/integration/export/manifest_helloworld.yaml: runtime: java
./tests/src/integration/export/manifest_helloworld.yaml: runtime: python
./tests/src/integration/export/manifest_helloworld.yaml: runtime: swift:3.1.1
./tests/src/integration/helloworld/manifest.yaml: runtime: ruby:2.5
```
or some "helloXXX" variant:
```
./tests/src/integration/helloworld/manifest.yaml: runtime: go:1.11
./tests/dat/manifest_hello_swift.yaml: runtime: swift
```

and "runtime" (version) variants for:
```
./tests/src/integration/runtimetests/manifest.yaml: runtime: nodejs:8
./tests/src/integration/runtimetests/manifest.yaml: runtime: php:7.1
./tests/src/integration/runtimetests/manifest.yaml: runtime: php:7.2
./tests/src/integration/runtimetests/manifest.yaml: runtime: php:7.3
./tests/src/integration/runtimetests/manifest.yaml: runtime: php
./tests/src/integration/runtimetests/manifest.yaml: runtime: python
./tests/src/integration/runtimetests/manifest.yaml: runtime: python:2
./tests/src/integration/runtimetests/manifest.yaml: runtime: python:3
./tests/src/integration/runtimetests/manifest.yaml: runtime: ruby:2.5
./tests/src/integration/runtimetests/manifest.yaml: runtime: swift:4.2
```

NOTE: we SHOULD have helloworld tests use "default" kind (not versioned) for each runtime language and a runtime test for each supported version. A PR to fix this issue SHOULD attempt to comprehensively fix the uniformity of tests accordingly.

[ and not have "default" kinds be tested as a side effect on another testcase of different purpose.]