Draft: Multivariate plotting

I often have the need to plot multiple variables into the same figure, for comparison and/or validation reasons. This MR makes saqc.plot a multivariate function and also quite a bit of refactoring.

saqc/funcs/tools.py

@@ -18,7 +18,7 @@ from typing_extensions import Literal
 from saqc.constants import FILTER_NONE, UNFLAGGED
 from saqc.core.register import processing, register
 from saqc.lib.plotting import makeFig
-from saqc.lib.tools import periodicMask
+from saqc.lib.tools import periodicMask, toSequence
 
 if TYPE_CHECKING:
     from saqc.core.core import SaQC
@@ -224,13 +224,12 @@ class ToolsMixin:
         self._flags[mask, field] = UNFLAGGED
         return self
 
-    @register(mask=[], demask=[], squeeze=[])
+    @register(mask=[], demask=[], squeeze=[], multivariate=True)
     def plot(
         self: "SaQC",
         field: str,
         path: Optional[str] = None,
         max_gap: Optional[str] = None,
-        history: Optional[Literal["valid", "complete"] | list] = "valid",
         xscope: Optional[slice] = None,
         phaseplot: Optional[str] = None,
         store_kwargs: Optional[dict] = None,
@@ -264,15 +263,6 @@ class ToolsMixin:
             before plotting. If an offset string is passed, only points that have a distance
             below `max_gap` get connected via the plotting line.
 
-        history : {"valid", "complete", None, list of strings}, default "valid"
-            Discriminate the plotted flags with respect to the tests they originate from.
-
-            * "valid" - Only plot those flags, that do not get altered or "unflagged" by subsequent tests. Only list tests
-              in the legend, that actually contributed flags to the overall resault.
-            * "complete" - plot all the flags set and list all the tests ran on a variable. Suitable for debugging/tracking.
-            * None - just plot the resulting flags for one variable, without any historical meta information.
-            * list of strings - plot only flags set by those tests listed.
-
         xscope : slice or Offset, default None
             Parameter, that determines a chunk of the data to be plotted
             processed. `xscope` can be anything, that is a valid argument to the ``pandas.Series.__getitem__`` method.
@@ -317,13 +307,12 @@ class ToolsMixin:
 
         fig = makeFig(
             data=data,
-            field=field,
+            fields=toSequence(field),
             flags=flags,
             level=level,
             max_gap=max_gap,
-            history=history,
             xscope=xscope,
-            phaseplot=phaseplot,
+            phaseplots=phaseplot,
             ax_kwargs=ax_kwargs,
         )