Engine: a Name: token reaches a defined name that holds periods

`Name:` read a name only up to the first period, so `Name:Sales.Q1` looked up `Sales` and
treated `Q1` as a method, and a workbook name called Sales.Q1 could not be used in a macro,
alone or as `Name:Sales.Q1.cell(1,1)`.

The name now runs through periods, and the longest defined name or table that exists and ends
at a period (or the end) is used; what follows is read as methods. So `Name:Data.row` is a
name called Data.row, and `Name:Sales.offset(1,0)` still moves Sales. When no name matches,
the error names the text before the first method, and a bad method after a dotted name is
still refused. Tests cover direct resolution, reference parameters, `$ref` and `{{...}}`,
with and without a chained method.

docs/macros.md

@@ -57,7 +57,9 @@ Methods narrow or move a range and chain: `col(2)` or `col("Amount")`, `row(1)`,
 `rows(2..)`, `cell(r,c)` (relative to the top-left cell; `cell(0,1)` is the cell above),
 `offset(r,c)`, `resize(h,w)`, `data` (without the header row), `below(n)` and `right(n)`.
 `col("Amount")` looks the name up in an input's header row, directly or after `data`; on a range
-without a header row it is refused.
+without a header row it is refused. A defined name can hold periods: `Name:Sales.Q1` is the name
+`Sales.Q1`, and `Name:Sales.Q1.cell(1,1)` its first cell, because the longest name or table that
+exists is used and methods follow it.
 
 Write a token as the whole value of a reference parameter (`cell`, `range`, `target`, keys ending
 in `Cell` or `Range`…), as `{"$ref": "Input.col(2)"}` anywhere, or as `{{Input.col(2)}}` inside