Changed: Helm: Make security context configuration overwritable

See merge request frontend/user-guide!13

- Update the docu regarding OXUIB-2744
- Docu for: OXUIB-2635: Automatically select top suggestion in to/cc/bcc on enter

- Improvements for the topic structure, step #2

- Fix the Docu for using AI functions while composing an email
- Check the visibility of the topic 'Sending emails later'

- Docu for: Hard to find the "copy to description" link
- Improved topic structure

- Check the mapping, linking and internal docu of the Inline Help, round #2

- Issue #192 Docu for: Missing translate options in AI dialog during mail compose
- Issue #197 Fix the outdated docu for 'Automatische Weiterleitung'

- Issue #188 Check and update the content of the Online Help startpage
- Issue #193 Check the mapping, linking and internal docu of the Inline Help

- Issue #185 OXUD-1266 Check the docu of the new features
- Copyright holder updated
- Issue #186 Fix for: OXUIB-2722 online help for connected clients misleading

- OXUD-1282 Update the Guard user docu
- OXUD-1254 Story OXUI-1349 As a user I can forward meeting invitations to others
- Issue #181 Docu for: Scheduled send cannot be canceled
- Issue #183 Check the german docu for missing translations of UI elements

OXUD-1272 Some updates for the Search instructions
OXUD-1274 Story OXUIB-2650 Sharing options of personal address book disabled
OXUD-1277 Additional information for email scheduled send
OXUD-1279 Enhancement: Make the main instructions easier to access

- OXUD-1270 Update the Guard docu due to the new settings pages

- OXUD-1260 Check the german docu for missing translations
- OXUD-1268 Check the docu for missing conformance attributes
- OXUD-1266 Check the docu of the new features

- OXUD-1231 Story OXUI-1306 As a user I can add categories to emails
- OXUD-1197 Story OXUI-1189 As a user I can schedule emails to be sent in the future
- OXUD-1265 Review and improve the linking of help topics

- OXUD-1261 Describe the undelete feature for permanently deleted emails