WixCop.exe is a built in formatting tool that comes with WiX toolset v3. This fixes `wix convert` command not beins able to run

…oring

It's not needed anymore.

Also rename `root_el` to `wix_el`.

WiX version 5 uses the same namespace.

It's the new default name for it

- The Keywords and Description items move under a new SummaryInformation element.
- Shuffle things around so that elements previously under the product element are now under the Package element.
- Rename SummaryCodepage in SummaryInformation to Codepage and remove a duplicate Manufacturer item.
- Remove InstallerVersion and let WiX set it to default value. (500 a.k.a Windows 7)

Since running `wix msi validate` with it set to `yes` causes an error.

… component

…` component

Due to limitations of the xml.etree.ElementTree library, add the items in the root element as a dictionary

This is a new default and makes authoring slightly simpler without any functional changes.

- Rename variables to be more clear about what they do:
- reorganise code
- simplify a few checks

…pRef`

With this, all the files are organised into Components,
each of which points to a Directory defined in the StandardDirectory element.
This simplifies the Feature element considerable as only thing it needs to
include everything in the built msi is a reference to `ApplicationComponents`

- rename for clarity
- remove unnecessary checks

…maryInformation elements directly

See [1]

[1] https://learn.microsoft.com/en-us/windows/win32/msi/guid

Also reduce duplication slightly by definig `build_dir`, `cx_freeze_dir` and `dist_dir`

- WiX Toolset v3 used to validate the msi package by default. In v5 that has moved to a new command, so add a new validation step to the script.

- Also emove the step that uses `insignia.exe` to sign the Dangerzone.msi with the digital signatures from its external cab archives.

  In WiX Toolset v4 and newer, insignia is replaced with a new command `wix msi inscribe`, but we tell wix to embed the cabinets into the .msi
  (That's what`EmbedCab="yes"` in the Media / MediaTemplate element does) so singning them separately is not necessary. [0]

  [0] https://wixtoolset.org/docs/tools/signing/