Add client-application-examples

[alexr-bq]

Adding link to https://github.com/vertica/client-application-examples

These contain examples for using client applications.

Make sure that you've checked the boxes below before you submit PR:

• [ x] I have read the contribution guidelines.
• [ x] I have added my project in alphabetical order to the relevant category.
• [ x] I have used the correct format: [item](link) - A short description ends with a period.
• [ x] I have an appropriate description with correct spelling and grammar.
• [ x] I know that this project was not listed before.
• [ x] I have added a pull request title in the format of Add Project-Name.