[RUN-AS-IF-FOSS] Add security_dashboard_access_level into ProjectFeatures

What does this MR do?

This MR makes it possible to enable/disable the "Security & Compliance" menu item from the project navigation.

Database review

This MR introduces a new column called security_and_compliance_access_level for the project_features table.

rake db:migrate:up

== 20210126030249 AddSecurityDashboardAccessLevelIntoProjectFeatures: migrating
-- add_column(:project_features, :security_and_compliance_access_level, :integer, {:default=>10, :null=>false})
   -> 0.0038s
== 20210126030249 AddSecurityDashboardAccessLevelIntoProjectFeatures: migrated (0.0039s)

rake db:migrate:down

== 20210126030249 AddSecurityDashboardAccessLevelIntoProjectFeatures: reverting
-- remove_column(:project_features, :security_and_compliance_access_level, :integer, {:default=>10, :null=>false})
   -> 0.0010s
== 20210126030249 AddSecurityDashboardAccessLevelIntoProjectFeatures: reverted (0.0033s)

Related to #290112 (closed)

Screenshots

When the feature is enabled

When the feature is disabled

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• [-] Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• [-] Label as security and @ mention @gitlab-com/gl-security/appsec
• [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• [-] Security reports checked/validated by a reviewer from the AppSec team