PY-22094 Include assert statements in CFG to resolve names in f-strings inside

Otherwise it's impossible to flow-sensitively resolve names referenced
inside such f-strings since we use the containing statement as the anchor
node in the graph.

python/testData/codeInsight/controlflow/assert.txt

@@ -1,10 +1,11 @@
 0(1) element: null
-1(2) READ ACCESS: isinstance
-2(3) READ ACCESS: s
-3(4) READ ACCESS: basestring
-4(5) READ ACCESS: isinstance
-5(6) READ ACCESS: x
-6(7) READ ACCESS: int
-7(8) ASSERTTYPE ACCESS: s
-8(9) ASSERTTYPE ACCESS: x
-9() element: null
+1(2) element: PyAssertStatement
+2(3) READ ACCESS: isinstance
+3(4) READ ACCESS: s
+4(5) READ ACCESS: basestring
+5(6) READ ACCESS: isinstance
+6(7) READ ACCESS: x
+7(8) READ ACCESS: int
+8(9) ASSERTTYPE ACCESS: s
+9(10) ASSERTTYPE ACCESS: x
+10() element: null

python/testData/codeInsight/controlflow/assertfalse.txt

@@ -1,6 +1,8 @@
 0(1) element: null
-1(5) READ ACCESS: false
-2(3) element: PyPrintStatement
-3(5) READ ACCESS: False
-4(5) element: PyPrintStatement
-5() element: null
+1(2) element: PyAssertStatement
+2(7) READ ACCESS: false
+3(4) element: PyPrintStatement
+4(5) element: PyAssertStatement
+5(7) READ ACCESS: False
+6(7) element: PyPrintStatement
+7() element: null

python/testData/codeInsight/controlflow/assertfalseargument.txt

@@ -1,7 +1,9 @@
 0(1) element: null
-1(6) READ ACCESS: False
-2(3) element: PyPrintStatement
-3(4) READ ACCESS: False
-4(6) READ ACCESS: f
-5(6) element: PyPrintStatement
-6() element: null
+1(2) element: PyAssertStatement
+2(8) READ ACCESS: False
+3(4) element: PyPrintStatement
+4(5) element: PyAssertStatement
+5(6) READ ACCESS: False
+6(8) READ ACCESS: f
+7(8) element: PyPrintStatement
+8() element: null