Bring SAST to Core - EOL TSLint and merge into ESLint

Full requirements listing in &2098 (closed)

Scope of this issue specifically

TSLint is now deprecated. We deprecate and end of life this scanner. TSLint functionality has been transitioned to ESLint, which will be moving to core in #34707 (closed)

Tasks

Update eslint to support analyzing typescript.
Update https://gitlab.com/gitlab-org/gitlab/blob/master/lib/gitlab/ci/templates/Security/SAST.gitlab-ci.yml to use eslint for typescript files.
Deprecate tslint repository
Deprecation notice in 13.2

Edited Jul 16, 2020 by Daniel Paul Searles