related fdo#70414 gbuild to ide: kdevelop

This provides kdevelop integration and generates one project file for each
old-style module (top level dir). This project file has:

- has four build configurations:
  - build the module of the project or build all of LibreOffice
  - for each of the above a debug and a nondebug build
- has seven launch targets:
  - running the unitchecks, the slowchecks and subsequentchecks
  - for each of the above once for the module and once for all
  - running LibreOffice interactively
- has custom include paths and thus provides full autocompletion

Change-Id: I6dd51133147d019fc403e3bd814bc6103df94cac
Reviewed-on: https://gerrit.libreoffice.org/6694
Reviewed-by: Björn Michaelsen <bjoern.michaelsen@canonical.com>
Tested-by: Björn Michaelsen <bjoern.michaelsen@canonical.com>