Propage errors from the init() mether

[MindaugasLaganeckas]

Is your feature request related to a problem? Please describe.
I have been looking into several issues related to propagating the syntax errors from mermaid to other clients, e.g. mermaid-cli. By inspecting the code of mermaid.js (

mermaid/src/mermaid.js

Line 122 in d040883

} catch (e) {

), I can see that all errors are caught on the mermaid level and never propagated to the clients. That is a problem described in several issues. One is here (mermaid-js/mermaid-cli#138)

Describe the solution you'd like
Make another function called init(), rename existing one to initThrowsErrors(). The new init() calls initThrowsErrors() and try-catch lives in init(). Then clients can choose either to call init() or initThrowsErrors()

Describe alternatives you've considered
Remove try-catch in the current implementation of init()
Reimplement parts of the init() in mermaid-cli

Additional context
Discussion in slack: https://mermaid-talk.slack.com/archives/CL256P19N/p1633101057039000