Fix Indexer/dashboard management sections references

[asteriscos]

Description

This pull request fixes many references to Dashboard management and Indexer Management sections in Wazuh dashboard.

Closes

• Discovered inaccurate path to custom branding page during testing for 4.9-alpha3 #7563

Checks

Docs building

• Compiles without warnings.

Code formatting and web optimization

• Uses three spaces indentation.
• Adds or updates meta descriptions accordingly.
• Updates the redirects.js script if necessary (check this guide).

Writing style

• Uses present tense, active voice, and semi-formal registry.
• Uses short, simple sentences.
• Uses bold for user interface elements, italics for key terms or emphasis, and code font for Bash commands, file names, REST paths, and code.

[Tostti]

LGTM ✅