Authentication and separate user support

• Adds support for basic authentication via username and password
• Adds support for different users

This mr changes application paths. If application is deployed on k8s cluster with ingress and specific paths configured, additional paths have to be configured for the ingress like so: https://gitlab.com/dependabot-gitlab/deploy/-/blob/main/main.tf#L171

Implements https://gitlab.com/dependabot-gitlab/dependabot/-/issues/80

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Allure report

allure-report-publisher generated test report!

rspec: ✅ test report for 45498699

+------------------------------------------------------------------+
|                        behaviors summary                         |
+-------------+--------+--------+---------+-------+-------+--------+
|             | passed | failed | skipped | flaky | total | result |
+-------------+--------+--------+---------+-------+-------+--------+
| controllers | 25     | 0      | 0       | 0     | 25    | ✅     |
| services    | 181    | 0      | 0       | 0     | 181   | ✅     |
| tasks       | 11     | 0      | 0       | 0     | 11    | ✅     |
| jobs        | 14     | 0      | 0       | 0     | 14    | ✅     |
| models      | 4      | 0      | 0       | 0     | 4     | ✅     |
| system      | 10     | 0      | 0       | 0     | 10    | ✅     |
+-------------+--------+--------+---------+-------+-------+--------+
| Total       | 245    | 0      | 0       | 0     | 245   | ✅     |
+-------------+--------+--------+---------+-------+-------+--------+