Synthesize root watch directories from queries on init

[ValdemarGr]

Every change rooted in the workspace (but not bazel*) should probably be watched? Maybe this is parameterizable?

[ValdemarGr]

I have added a --watch parameter for now.

I don't think local_repository type of rules are harder than the current workspace.

Maybe just watch all
$$\texttt{local-repositories} \cup \texttt{current-workspace} \backslash \set{\texttt{bazel-bin}, \texttt{bazel-out}, \texttt{bazel-testlogs}, \texttt{bazel-current-workspace}}$$
ibazel also watches every change ibazel only reacts to changes in the build graph, which means that dynamically expanded functions such as glob are not respected; it seems to be a difficult task to precisely watch all the correct locations. For new build target creation I don't see how you can construct an algorithm that catches such events without watching everything.

I think skipping creations will be bad DX. So maybe add flags for controlling the watching config (explicitly add/omit paths).