sentry: Enable to pass main package name as init_sentry parameter
It is useful to compute the release name for sentry when the SWH_MAIN_PACKAGE environment variable is not defined.
Related to swh/meta#4949 (closed).
It is useful to compute the release name for sentry when the SWH_MAIN_PACKAGE environment variable is not defined.
Related to swh/meta#4949 (closed).