xquery4 2.7.0

This package has no dependencies.

Schema-aware typing: a validated node now carries its schema type through atomization, type
tests, casts and `fn:idref`. QT3 goes from 427 to 257 failing of 31,331. Requires
PhoenixmlDb.Core 2.2.0.

### Security: limits and resource policy with untrusted queries (GHSA-6whf-hvfp-757r)

Only hosts that evaluate queries from untrusted parties are affected.

- A module loaded with `fn:load-xquery-module` runs inside the caller's limits, cancellation
 token and host function replacements. It ran with none of them.
- `RegexMatchTimeout` now bounds XSD `pattern` facets in casts, `validate` and schema loading.
 New `CompilationOptions.RegexMatchTimeout` and `XsdSchemaProvider.PatternMatchTimeout` for
 schemas imported at compile time.
- Module import chains and nested `fn:load-xquery-module` calls are capped at 64 deep
 (`XQST0059`, `FOQM0003`) and schema nesting at 512; `fn:parse-xml` is linear in nesting depth,
 can be cancelled, and does not need a deep stack (it stopped the process on Windows' 1 MB
 stack).
- `XsdSchemaProvider.Add` / `AddFromString` take a resource policy for the schema's own
 includes and imports.
- New `IResourceResolver.ResolveContent` and `SuppliesAllContent`: a host can supply the
 content of modules, schemas, documents, JSON and text itself, which removes the gap between
 authorising a location and opening it.

Not fixed: when the host neither refuses a location nor supplies its content, check-then-open
remains.

### Schema-aware typing

- **A validated node atomizes to its typed value.** `data()` of a node a schema types as
 `xs:integer`, a schema-defined restriction, a list or a union gives values of that type, and
 operators and comparisons see them. A node whose type has element-only content has no typed
 value (`FOTY0012`).
- **Validated nodes are instances of their schema-defined and anonymous types**, so
 `element(*, p:T)`, `schema-element(p:e)` and `schema-attribute(p:a)` match, substitution
 groups included.
- **Casts to schema-defined types.** A list type yields its items; a union is tried member by
 member; a non-string value is checked in its canonical form.
- **`fn:idref` finds elements and attributes a schema types as `xs:IDREF` or `xs:IDREFS`**, as
 it already did for DTD-declared attributes.
- **Unprefixed type names take the default element/type namespace** of
 `import schema default element namespace`, and a library module's own prefix names the types
 of a schema it imports.

Nodes that were not validated are unaffected.

### Changed behaviour to check on upgrade

- **`validate` raises the codes the specification assigns.** `validate strict` of an element
 with no declaration is `XQDY0084`.
- **Atomizing a validated node with element-only content is `FOTY0012`.** It used to give the
 string value. `string()` is unaffected.
- **A date or dateTime outside the supported range is `FODT0001`**, not `FORG0001`
 (`xs:date('25252734927766555-07-28')`).
- **A reserved name in a named function reference is `XPST0003`**, not `XPST0017`
 (`attribute#0`, `element#1`, `if#1`).
- **`fn:unparsed-text` with a named encoding reports `FOUT1190`** for content that is not valid
 in it, and `fn:unparsed-text-available` answers false for an encoding the runtime refuses
 (`utf-7`) where it used to throw.
- **A schema import's static rules are checked first.** Binding `xml` or `xmlns` is `XQST0070`,
 a prefix with an empty target namespace is `XQST0057`, two imports of one namespace are
 `XQST0058`. Each used to be `XQST0059`.
- **An imported module file must declare the namespace it was imported for** (`XQST0059`), and
 an external variable with no value is `XPDY0002`.
- **`in-scope-prefixes()` does not give the empty prefix for an element parsed with
 `xmlns=""`** (#105).
- **`$err:code` and other qualified local variables work inside a library module.**
- **A map constructor entry whose key begins with a prefixed name keeps its whole value.**

### API

- `ISchemaProvider.HasIdrefTypedValue(XdmTypeName, string)`, default `false`, and further
 `ISchemaProvider` members, each with a default implementation. Custom providers compile
 unchanged.
- `IResourceResolver.ResolveContent(ResourceRequest)` / `SuppliesAllContent` (security, above).
- `XQueryParseException.ErrorCode` returns the code that leads the message for any error code,
 not only `XPST`/`XQST` ones.

### `xquery` CLI (ships on `cli-v2.7.0`)

- Runs on **PhoenixmlDb.Xslt 2.7.0**, so `fn:transform` from a query gets the 2.7.0 engine,
 including the GHSA-xxjq-rwpx-m5ww fixes and #314 (a string result is no longer parsed as XML).
- **Parsed `xmlns=""` elements keep their undeclaration in the CLI's output** (#105).