[MDEP-695] Improve mvn dependency:tree - add option to generate mermaidjs flowchart diagram format

**[Emanuel Ciuca](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=eciuca)** opened **[MDEP-695](https://issues.apache.org/jira/browse/MDEP-695?redirect=false)** and commented

While trying to generate some diagrams for maven module dependencies I found mermaidjs flowchart diagrams to be most suitable for large graphs. (see [https://mermaid-js.github.io/mermaid/#/flowchart](https://mermaid-js.github.io/mermaid/#/flowchart)))

Here is an example of a graph I generated for one of the projects I work on:

```java
graph LR

module-1 --> |compile| module-2
module-3 --> |compile| module-4
module-3 --> |test| module-5
module-3 --> |compile,test| module-2
module-3 --> |test| module-1
```

I would be helpful to be able to generate this diagram for a multi-module maven project

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**Affects:** waiting-for-feedback

**Attachments:**
- [demo.svg](https://issues.apache.org/jira/secure/attachment/13002797/demo.svg) (_12.36 kB_)

Start by locating the dependency:tree goal and its existing output options in the Maven Dependency Plugin. Define the Mermaid flowchart output for the module dependency graph, including dependency scopes such as compile and test, and verify that a multi-module project produces a valid diagram matching the requested example.

Written by the indexing model from the issue text.