Feat(Template model): Added description to template

[Skraye]

Kestra do not support description for template.

Added the property in the Template model, then add test to verify the description is well handled

#721

close #721

[tchiotludo]

Can you also add the description on Templates.vue please like here :

kestra/ui/src/components/flows/Flows.vue

Lines 72 to 78 in 0bc9485

	&nbsp;<markdown-tooltip
	:id="row.item.namespace + '-' + row.item.id"
	:description="row.item.description"
	:title="row.item.namespace + '.' + row.item.id"
	:modal="true"
	/>
	</template>

[tchiotludo]

You have forgot the import on vue, everything is ok. thanks 👍