Added Bulgarian translation for security component
minor #10141 [Security] added Bulgarian translation (RoumenDamianoff)

This PR was submitted for the 2.3-dev branch but it was merged into the 2.3 branch instead (closes #10141).

Discussion
----------

[Security] added Bulgarian translation

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        |

Commits
-------

8fceeac Added Bulgarian translation for security component