Dividers and tooltips cleanup

[JuanjiJG]

Hello all,

This Pull Request adds even more adjustments and cleans up CSS in the app. The included changes are:

• Removed an unused CSS class and reviewed another one to fix a tooltip problem on Manager/Configuration.
  • This fix adds a class to almost every md-divider component throughout the app.
• Removed almost every md-tooltip component and replaced with the same system as Kibana's.
  • There's still Angular tooltips on Agents General until we can find a replacement for showing scans correctly.
• Some flex adjustments in Agents Preview.
• Removed bottom border from Kibana search bar.
• Removed unused images from the img folder.
• Added line height to PCI Description tabs.
• Added missing spaces in Settings.

I hope this to be useful for the project.

Best regards,
Juanjo

[havidarou]

LGTM!