[feature] Outgoing federation of avatar/header descriptions (#4270)

Signed-off-by: nicole mikołajczyk <git@mkljczk.pl>

# Description

This implementation is compatible with Iceshrimp.NET, Pleroma and Chuckya, which already support federated avatar/header descriptions. I will add support for incoming descriptions federation in this or another PR (depending on when this one gets merged).

## Checklist

Please put an x inside each checkbox to indicate that you've read and followed it: `[ ]` -> `[x]`

If this is a documentation change, only the first checkbox must be filled (you can delete the others if you want).

- [x] I/we have read the [GoToSocial contribution guidelines](https://codeberg.org/superseriousbusiness/gotosocial/src/branch/main/CONTRIBUTING.md).
- [ ] I/we have discussed the proposed changes already, either in an issue on the repository, or in the Matrix chat.
- [x] I/we have not leveraged AI to create the proposed changes.
- [x] I/we have performed a self-review of added code.
- [x] I/we have written code that is legible and maintainable by others.
- [ ] I/we have commented the added code, particularly in hard-to-understand areas.
- [ ] I/we have made any necessary changes to documentation.
- [ ] I/we have added tests that cover new code.
- [x] I/we have run tests and they pass locally with the changes.
- [x] I/we have run `go fmt ./...` and `golangci-lint run`.

Reviewed-on: https://codeberg.org/superseriousbusiness/gotosocial/pulls/4270
Co-authored-by: nicole mikołajczyk <git@mkljczk.pl>
Co-committed-by: nicole mikołajczyk <git@mkljczk.pl>

1 files changed, 12 insertions, 0 deletions

diff --git a/internal/typeutils/internaltoas.go b/internal/typeutils/internaltoas.go
index 4762e3c8b..3feecaa9b 100644
--- a/internal/typeutils/internaltoas.go
+++ b/internal/typeutils/internaltoas.go
@@ -348,6 +348,12 @@ func (c *Converter) AccountToAS(
 			avatarURLProperty.AppendIRI(avatarURL)
 			iconImage.SetActivityStreamsUrl(avatarURLProperty)
 
+			if a.AvatarMediaAttachment.Description != "" {
+				nameProp := streams.NewActivityStreamsNameProperty()
+				nameProp.AppendXMLSchemaString(a.AvatarMediaAttachment.Description)
+				iconImage.SetActivityStreamsName(nameProp)
+			}
+
 			iconProperty.AppendActivityStreamsImage(iconImage)
 			accountable.SetActivityStreamsIcon(iconProperty)
 		}
@@ -382,6 +388,12 @@ func (c *Converter) AccountToAS(
 			headerURLProperty.AppendIRI(headerURL)
 			headerImage.SetActivityStreamsUrl(headerURLProperty)
 
+			if a.HeaderMediaAttachment.Description != "" {
+				nameProp := streams.NewActivityStreamsNameProperty()
+				nameProp.AppendXMLSchemaString(a.HeaderMediaAttachment.Description)
+				headerImage.SetActivityStreamsName(nameProp)
+			}
+
 			headerProperty.AppendActivityStreamsImage(headerImage)
 			accountable.SetActivityStreamsImage(headerProperty)
 		}