Bookworm bug fixes

[thelamer]

This fixes bugs regarding multi monitor and errant clicks when using alt+tab for going in and out of the window with a new noVNC version form KasmVNC.

This adds two new ENV variable:

• NO_DECOR- Can be used for people that run downstream apps in PWA mode to not render in window decorations and feel more seemless.
• NO_FULL- The new default behavior for the baseimage running openbox is to fullscreen every open window, this is something we do where we can in single apps, but it has proven to be inconsistent with changing window names and is just another maintenance hassel. If users no longer want this behavior it is an env var that can be set at runtime or buildtime to be disabled.

This replaces the default clearlooks blue theme with something more modern specifically Afterpiece

The readme has been trimmed down to reference the master branch that will be kept up to date.

[LinuxServer-CI]

I am a bot, here are the test results for this PR:
https://ci-tests.linuxserver.io/lspipepr/kasmvnc-base/debianbookworm-0f844fee-pkg-0f844fee-dev-9e266f05b837cbc8a4440f21ae5b4b6f0fe2bf66-pr-42/index.html
https://ci-tests.linuxserver.io/lspipepr/kasmvnc-base/debianbookworm-0f844fee-pkg-0f844fee-dev-9e266f05b837cbc8a4440f21ae5b4b6f0fe2bf66-pr-42/shellcheck-result.xml

Tag	Passed
amd64-debianbookworm-0f844fee-pkg-0f844fee-dev-9e266f05b837cbc8a4440f21ae5b4b6f0fe2bf66-pr-42	✅
arm64v8-debianbookworm-0f844fee-pkg-0f844fee-dev-9e266f05b837cbc8a4440f21ae5b4b6f0fe2bf66-pr-42	✅