Improve package_form and resource_form

[mjanez]

The templates are used for customizing the dataset/resources form in the dataset schema. This addition enhances the flexibility of the extension by allowing users to modify the resource form according to their specific requirements.

The addition of form_groups simplifies metadata entry for the editor user, as well as facilitates the visualization of the metadata, grouped by thematic categories.

form_groups schema definition:

ckanext-schemingdcat/ckanext/schemingdcat/schemas/geodcatap_es/geodcatap_es_dataset.yaml

Lines 12 to 59 in 06f9302

	schema_form_groups:
	# Basic Info parties form_page (#1)
	- form_group_id: title
	label:
	en: Title
	es: Título
	fa_icon: fa-sticky-note
	- form_group_id: general_info
	label:
	en: General information
	es: Información general
	fa_icon: fa-info-circle
	- form_group_id: identification
	label:
	en: Dataset identification
	es: Identificación del conjunto de datos
	fa_icon: fa-id-card
	- form_group_id: notes
	label:
	en: Abstract
	es: Resumen
	fa_icon: fa-file-text
	- form_group_id: vocabs
	label:
	en: Vocabs information
	es: Información de vocabularios
	fa_icon: fa-database
	- form_group_id: contact
	label:
	en: Contact information
	es: Información de contacto
	fa_icon: fa-address-book
	# Responsible parties form_page (#2)
	- form_group_id: publisher
	label:
	en: Publisher information
	es: Información del publicador
	fa_icon: fa-user
	- form_group_id: maintainer
	label:
	en: Maintainer information
	es: Información del mantenedor
	fa_icon: fa-server
	- form_group_id: author
	label:
	en: Author information
	es: Información del autor
	fa_icon: fa-pencil-square-o

Metadata field added to form_group:

ckanext-schemingdcat/ckanext/schemingdcat/schemas/geodcatap_es/geodcatap_es_dataset.yaml

Lines 190 to 200 in 06f9302

	# Graphic overview (O)
	- field_name: graphic_overview
	label:
	en: Graphic overview of the dataset
	es: Descripción gráfica del conjunto de datos
	display_snippet: schemingdcat/display_snippets/graphic_overview.html
	form_placeholder: http://example.com/dataset.jpg
	help_text:
	en: "Graphic that provides an illustration of the dataset."
	es: "Gráfico que ilustra el conjunto de datos."
	form_group_id: general_info

Metadata package form template: