Add support for localized glossary labels and descriptions

[mdouchin]

• Ticket : #20

• [x] Add new fields label_fr and description_fr

• [x] Create a new view v_glossarywhich transforms the glossary data into a simple JSON

• [x] Use this view in the view v_contact, v_dataset & v_link and call the JSON with a session variable pgmetadata.locale

• [x] Modify the HTML export function(s) to set this variable via SET SESSION "pgmetadata.locale" = 'fr';

• [ ] Add a way to choose the locale within QGIS, for example with a combobox in the dock toolbar

• [ ] Use this locale when calling the HTML function

[mdouchin]

@Gustry could please you work on the last 2 checkboxes i.e. the use of the new version of the function inside QGIS ? SELECT pgmetadata.get_dataset_item_html_content('{schema}', '{table}', '{locale}');

• The locale must be taken from the QGIS current locale, and tested agains a hard-coded list of available locales ('en', 'fr')
• We should add an easy way to swich from available locales: what about a simple combobox in the dock toolbar ?

[Gustry]

Ok yes ! Looks cool ! Can we merge it like this ? I will add a test as well, just to be sure.

How will it work for the LWC module side ?

[mdouchin]

We can merge like this and open a new PR for the modification in the Python code

For the Lizmap module, see https://github.com/3liz/lizmap-pgmetadata-module/issues/6