Feature: Add edit view

[SchoolGuy]

Fixes #66

This PR adds the ability to edit Cobbler items (with the exception of network interfaces). Furthermore the PR switches from the custom XML-RPC API Client types to native Map and Array types. Lastly, this PR updates the eslint configuration to include prettier.

For the purpose of editing Cobbler items, I have introduced a second form on the same page that is read-only which contains the fields that are not editable. The edit view is able to set non string fields to inherit via a checkbox that can be found underneath. Dictionary/Map type fields are having the same issues as the CLI with ordering (see cobbler/cobbler#3797).

Developing with the Web UI seems to be a bit annoying at the moment because we don't save the credentials and token in memory and with every hot-reload this token ist lost. As such one needs to manually log out and in to have a valid token. This was already the case before but wasn't as evident since many read-only methods don't actually validate the token.

Since Templates and Snippets are not items from a backend perspective they cannot be edited, copied or renamed at the moment.

Screenshots:

Read view with read-only fields:

Edit view:

Cancel confirmation:

Save button:

[SchoolGuy]

Adding and removing Map keys works now. The issue is submitting them because the datatype is not Map but instead it is a general object, this however needs to be fixed everywhere in the stack.

Edit: Editing lists is already working.

[SchoolGuy]

Editing Dictionaries and Lists works for Distro but there are quite some bugs that need to be smoothed out. Changing from inherit to non inherit and vice-versa doesn't work yet.

[SchoolGuy]

Now disabling the input for fields that are marked as inherited is working for Distros.

[SchoolGuy]

Switching between inherited and non-inherited values is working now. Editing lists and maps is working now. As such there is now some bugfixing and code-deduplication to do. Other then that the approach has to be put into place with non-distro items.

[SchoolGuy]

Before merging this PR I will need to do some manual testing. Automatic testing is not feasible since the changes are still too rapid to work reliably without eating too much time.

[SchoolGuy]

I found a few small things but overall it seems that editing items via the UI seems to work quite okay. I haven't encountered any major issues so far.

This means I will merge this PR and implement other missing features in follow-up PRs. I don't believe though that after merging this a first alpha can be tagged. For this too much functionality is missing at the moment.