Generic composer tool support

[SamMousa]

Describe the feature
Currently all tools need to be manually registered in the code (tools.ts) of this package.

Version
Feature is not in master

Underlying issue
Function addTools uses a large switch statement and exact matching.

Describe alternatives
I propose adding a prefix for composer; for example: composer/scrutinizer/ocular would install the scrutinizer/ocular tool.

Additional context
This feature would reduce load because specific tools don't need to be added if they are available as composer package.

Are you willing to submit a PR?
Yes!

[shivammathur]

What would be the advantage in your opinion of adding this feature as compared to adding a step to install composer packages after setup-php.

I think composer prefix would be redundant, scrutinizer/ocular or anything matching user/tool can be passed to composer.

[SamMousa]

Good point on the redundancy of a prefix. My main reason for this feature request is that I need to install global composer package x and don't want to create a PR in this repo for every package.

I'm definitely flexible in the way we organise it, being a part of the tools syntax or a separate part of the config both will work fine and is up to your preference I guess

[SamMousa]

23393c4

[shivammathur]

Added in 2.11.0.