Support for overriding properties in Spring Boot apps

[mattcobley]

It would be great if the ability to override values for properties was made available when running/debugging Spring Boot applications.

This would allow a file like application.properties - which might contain variables instead of real values for use with something like Octopus Deploy - to be left as they are, but values for running locally to be specified in the debug config, in a similar manner to the "override properties" feature for Spring Boot apps in Spring Tool Suite:

[yaohaizh]

This issue was moved to microsoft/vscode-java-debug#451