Meta-ticket: Move undirected methods from generic_graph to graph

[mo271]

From a suggestion by dcoudert (#24634 comment:10): Let's move some of the methods that are actually only valid for undirected graphs from generic_graph to graph.

Methods to be moved:

a. is_planar b. is_drawn_free_of_edge_crossings c. ... (are there more?)

Things to be done:

1. Move method to new file
2. add correct @doc_index
3. remove line from the doc in the beginning of the file generic_graph
4. Fix the references to methods in the SEEALSO section ...
5. ... also for other methods referencing the moved method
6. ... is there more?

Please help editing these two lists.

Tickets

• 33776 move method distance_graph to graph.py

CC: @dcoudert

Component: graph theory

Issue created by migration from https://trac.sagemath.org/ticket/24648

[dcoudert]

comment:1

We should not move is_planar and is_drawn_free_of_edge_crossings but correct them

sage: G = graphs.Grid2dGraph(3,3)
sage: G.is_planar()
True
sage: D = DiGraph(G)
sage: D.is_planar()
False

A directed graph can be planar.

[dcoudert]

Description changed:

--- 
+++ 
@@ -17,3 +17,6 @@
 2. ... is there more?

 Please help editing these two lists. 
+
+**Tickets**
+- #33776 move method `distance_graph` to `graph.py`