A new UI setting was introduced to allow users to run unsigned binaries
without any input from the user. Defaults to false which means if a binary
is unsigned we will ask the user what to do next.

I moved and modified the logic from CliManager.download to a separate
http client based on okhttp and retrofit. The refactor will allow us
to easily add new steps in the main download method, and also to easily
download new resources. Long term we could also re-use the okhttp client
to avoid setting twice the same boilerplate (proxy which is missing from CLIManager,
hostname verification and other tls settings) between cli downloader and the rest client

From the same source where the cli binary was downloaded.
Some of the previous classes like download result were updated to incorporate
details like where the file was saved or whether a file was found on the remote

`allowUnsignedBinaryWithoutPrompt` was caching the initial value read from the
store, which required a restart of Toolbox for the real value to reflect.

A pop-up dialog is displayed asking the user if he wants to run an unsigned
cli version. The pop-up can be skipped if the user configures the `Allow unsigned binary execution without prompt`

…ication

Adds logic to verify the CLI against a detached GPG signature with the help of bouncycastle library

This is the key that validates if the gpg signature was tampered

Initially I thought about embedding it as a const string in the code
but the string is too big, best to save it as resource file.
The code changes are mostly related to loading the key from the file.

Signature verification some operations that are cpu bound that are light, like
decoding and decompressing signature data, some medium CPU intensive operations
like the cryptographic verifications and a couple of blocking IO operations:
- reading the cli file
- reading the signature file
- reading the public key file

These last should run on the IO thread to not block the main thread from drawing the screen.
The cpu bound operation should run on the default thread.

previous implementation was selecting only the first key ring from the public key file
which turns out to be wrong. Instead, we should keep all the key rings and search signature
key id in all the key rings.

Otherwise, at the next Toolbox restart the signature will no longer be verified,
and we run into the risk of running unsigned binaries.

`Files.readAllBytes()` uses direct buffers internally which can be filled up quickly when
called repeatedly in coroutines, as these buffers are not released quickly by the GC.
The scenario can be reproduced by trying to login a couple of times one after the other with
signature verification failing each time.

Instead, we can avoid memory issues by streaming the cli and feed only blocks of bytes into the signature calculation.

When there is no signature and the user allowed running of unsigned binaries without prompt

A major feature was added