feat: add request coalescing for isolated tools

[nichmor]

Overview

During installation of isolated tools, we request it for all platforms concurrently. This means that , in case of 4 platforms, we will try to install it 4 times.

This PR introduce a request coalescing system, that will allow only one resolution and instalation process to happen.

Some implementation details:

• impl is heavily inspired by https://github.com/conda/rattler/blob/main/crates/rattler_repodata_gateway/src/gateway/mod.rs#L180 and https://github.com/prefix-dev/rip/blob/main/crates/rattler_installs_packages/src/wheel_builder/mod.rs#L39
• I've removed caching of system tool, as it only complicate branchning during the cache coalescing and it just a new struct that wraps the command.

[tdejager]

Looks good! Could you create a test that might test for parallel installs using tokio spawn and the multihreaded executor?

[nichmor]

failure of CI is expected because of this:
#2601 (comment)