Exception Handling Improvements

[tinakurian]

Issue Overview

Exception handling in Launcher Backend can be improved.

Currently, there are some examples of the following:
"RuntimeException" and "IllegalArgumentException" being thrown:
public Optional<GitHook> getHook(final GitRepository repository, final URL url) throws IllegalArgumentException { ... }

Exceptions are caught and swallowed:

this.httpClient.executeAndConsume(request, response -> {
            if (!response.isSuccessful()) {
                String message = response.message();
                try {
                    ResponseBody body = response.body();
                    if (body != null) {
                        message = body.string();
                    }
                } catch (IOException io) {
                    // ignore
                }
                throw new HttpException(response.code(), message);
            }
        });

Perhaps, exception handling is an area that we can consider improving.

Expected Behaviour

Generic exceptions should never be thrown.
Exceptions should never be swallowed.

Current Behaviour

Generic exceptions are thrown.
Exceptions are swallowed in some places.