Mermaid support

[mtrakal]

• Added support for generating Mermaid format in markdown.
• Unify format of params for Kotlin DSL (all use Set)
• Added outputFormat and outputFilePath to moduleGraphAssert
• All Gradle tasks are in same module graph assert group

[jraska]

Hey, thanks for the proposal, I appreciate your time spent on it. I will though not accept it as it is way too big, changing too many things and adding feature I'm not sure I want to maintain, sorry.

From the PR description:

Added support for generating Mermaid format in markdown. Unify format of params for Kotlin DSL (all use Set) Added outputFormat and outputFilePath to moduleGraphAssert All Gradle tasks are in same module graph assert group

Each of these separate points could be one PR. 🤔 + I see some other changes bloating the PR like formatting changes, logic refactor etc.

I understand the main purpose was adding the "Meimaid support".

1. What is it? Any links?
2. Why should this plugin support it? It is the first time to my knowledge there if a feature request like this, therefore I don't feel like it should belong to the plugin. If you require this for your project I would recommend a fork or local copy.

[mtrakal]

Mermaid is "clone" of Graphviz. It's supported by GitHub Markdown - diagrams. So it allow draw into readme files and show it on github.

But understand, that's big... I'll try to maintain for us in fork.