To support recovery of malformed binding property names like `([a)`,
`[a`, or `()`, the binding parser needs to be more permissive w.r.t. the
kinds of bindings it can detect. This is difficult to do maintainably
with a regex, but is trivial with a "hand-rolled" string parser. This
commit refactors render3's binding attribute parsing to use this method
for multi-delimited bindings (namely via the `()`, `[]`, and `[()]`)
syntax, making the way recovery of malformed bindings in a future patch.
Note that we can keep using a regex for prefix-only binding syntax
(e.g. `bind-`, `ref-`) because validation of the binding is complete
once we have matched the prefix, and the only thing left to do is check
that the binding identifier is non-empty, which is trivial.
Part of #38596
PR Close#39375
3241d922fc