Indent expressions in JSXAttributes relative to the attribute’s name

Indent expressions in JSXAttributes relative to the attribute’s name

* lisp/progmodes/js.el (js-jsx--syntax-propertize-tag): Refer to the
beginning of a JSXExpressionContainer’s associated JSXAttribute (so
line numbers can be calculated later).
(js-jsx--text-properties): Also clear the new text property
js-jsx-expr-attribute.

(js-jsx--indenting): Remove.
(js-jsx--indent-col, js-jsx--indent-attribute-line): New variables.
(js-jsx--indentation): Instead of alternating between two separate
column calculations, neither necessarily correct, bind the JSX column
such that the second call to js--proper-indentation can use it as a
base column.
(js--proper-indentation): Use JSX as the base column for some indents
while indenting JSX.

* test/manual/indent/jsx.jsx: Add more tests for expression indents.