Align XML_Document and XML_Element APIs more. (#9233)

- Added `to_table` extensions on some core types.
- Added ICON to `Any.to`.
- Added ICON to `Column.info`, `Table.info`, `DB_Column.info` and `DB_Table.info`.
- Added defaults to `Table.cross_tab` and `DB_Table.cross_tab`.
- Added `name`, `get`, `at`, `inner_xml` and `outer_xml` to `XML_Document`.
- Added constants into left hand side of simple expressions.
- Added widget to `get` and `at` on `XML_Document` and `XML_Element`. (Some bug in annotation code with Dmitry)
- Altered `get` and `at` to not allow XPath and just get direct child/attribute values.
- Added `get_xpath` to `XML_Document`.
- Renamed `get_elements_by_tag_name` to `get_descendants_by_tag_name` and added new `get_children_by_tag_name`.
- Added `child_names` and `attribute_names` to `XML_Document` and `XML_Element`.

Author: jdunkerley

CHANGELOG.md

@@ -620,6 +620,7 @@
 - [Allow `copy_to` and `move_to` to work between local and S3 files.][9054]
 - [Adjusted expression handling and new `Simple_Expression` type.][9128]
 - [Allow reading Data Links configured locally or in the Cloud.][9215]
+- [Update the XML methods and add more capabilities to document.][9233]
 
 [debug-shortcuts]:
   https://github.com/enso-org/enso/blob/develop/app/gui/docs/product/shortcuts.md#debug
@@ -896,6 +897,7 @@
 [9054]: https://github.com/enso-org/enso/pull/9054
 [9128]: https://github.com/enso-org/enso/pull/9128
 [9215]: https://github.com/enso-org/enso/pull/9215
+[9233]: https://github.com/enso-org/enso/pull/9233
 
 #### Enso Compiler
 

distribution/lib/Standard/Base/0.0.0-dev/src/Any.enso

@@ -21,6 +21,7 @@ from project.Function import const
 @Builtin_Type
 type Any
     ## GROUP Conversions
+       ICON convert
        Generic conversion of an arbitrary Enso value to requested type.
        Delegates to appropriate `.from` conversion method, if it exists.
        If such method doesn't exist, `No_Such_Conversion` panic is raised.