Update plugin versions under Add to an existing application programatically

[natalie-bernhard]

Use an API request to get the latest maven/gradle plugin versions for the Add to an existing application section on the start page.

[steven1046]

This will have to happen on the backend due to rate limiting by Github.

[natalie-bernhard]

Maven plugin versions API call: https://search.maven.org/solrsearch/select?q=g:io.openliberty.tools+AND+a:liberty-maven-plugin&core=gav&rows=20&wt=json

[natalie-bernhard]

Gradle plugin versions API call: https://search.maven.org/solrsearch/select?q=g:io.openliberty.tools+AND+a:liberty-gradle-plugin&core=gav&rows=20&wt=json

[natalie-bernhard]

We cannot make an API request to the above links due to CORS issues. Try to see if there is another source for us to pull the version numbers from.