set MAVEN mode as the default mode

[monperrus]

follow up of #347

MAVEN mode should give better bindings, better imports and overall better results.

[algomaster99]

@monperrus Using the maven mode requires passing --resolve-classpath-from and the client has to give it the path to a valid maven project. I think we should not make it the default mode because if someone does not want to use the above flag, they will have to explicitly specify that they want the current default mode.

Maybe we can highlight in the README that we recommend using maven mode. What do you think?

[monperrus]

Good point. In Maven mode, regardless it's default or not, we can automatically infer the arguments to be given to --resolve-classpath-from

[algomaster99]

More context: #598 (comment).