Update sentence casing in "Security and Compliance" menu items

What does this MR do and why?

Rename "Discover" to "Security capabilities"

Within the "Security and Compliance" menu.

Rename "Configuration" to "Security configuration"

Within the "Security and Compliance" menu. We also make sure that all the existing "Security Configuration" breadcrumbs match the sentence casing. We also fix a few sentence casing issues in children pages:

• DAST Configuration => DAST configuration
• SAST Configuration => SAST configuration

The choice not to rename "API Fuzzing Configuration" to "API fuzzing configuration" was made deliberately, because there are so many wrong cased "Fuzz"es in the code base, that it would blow up the scale of this changeset too much.

Screenshots or screen recordings

What	Before	After	Note
Project "S&C > Discover" -> "S&C > Security capabilities"			-
Group "S&C Discover" -> "Security capabilities"			See also this discussion
Project "S&C > Configuration" -> "S&C > Security configuration"			-
SAST Configuration -> SAST configuration			Also updated "Security configuration" in the breadcrumb
API Fuzzing Configuration			"Security configuration" breadcrumb only, see also this discussion
Fuzz testing corpus management			"Security configuration" breadcrumb only, see also this discussion
DAST Configuration -> DAST configuration			Also updated "Security configuration" in the breadcrumb
DAST profile library			"Security configuration" breadcrumb only

How to set up and validate locally

1. For "Security capabilities" to be available, the quickest way is to change show_discover_project_security? and show_discover_group_security? to return true.
2. All the other items should be available in Groups / Projects in the GDK

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #378546 (closed)