git: Improve self-hosted provider support and Bitbucket integration (#42343)

This PR includes several minor modifications and improvements related to
Git hosting providers, covering the following areas:

1. Bitbucket Owner Parsing Fix: Remove the common `scm` prefix from the
remote URL of self-hosted Bitbucket instances to prevent incorrect owner
parsing.
[Reference](https://github.com/gitkraken/vscode-gitlens/blob/a6e3c6fbb255116507eaabaa9940c192ed7bb0e1/src/git/remotes/bitbucket-server.ts#L72-L74)
2. Bitbucket Avatars in Blame: Add support for displaying Bitbucket
avatars in the Git blame view.
<img width="2750" height="1994" alt="CleanShot 2025-11-10 at 20 34
40@2x"
src="https://github.com/user-attachments/assets/9e26abdf-7880-4085-b636-a1f99ebeeb97"
/>
3. Self-hosted SourceHut Support: Add support for self-hosted SourceHut
instances.
4. Configuration: Add recently introduced self-hosted Git providers
(Gitea, Forgejo, and SourceHut) to the `git_hosting_providers` setting
option.
<img width="2750" height="1994" alt="CleanShot 2025-11-10 at 20 33
48@2x"
src="https://github.com/user-attachments/assets/44ffc799-182d-4145-9b89-e509bbc08843"
/>


Closes #11043

Release Notes:

- Improved self-hosted git provider support and Bitbucket integration

crates/settings/src/settings_content/project.rs

@@ -543,7 +543,7 @@ pub enum DiagnosticSeverityContent {
 pub struct GitHostingProviderConfig {
     /// The type of the provider.
     ///
-    /// Must be one of `github`, `gitlab`, or `bitbucket`.
+    /// Must be one of `github`, `gitlab`, `bitbucket`, `gitea`, `forgejo`, or `source_hut`.
     pub provider: GitHostingProviderKind,
 
     /// The base URL for the provider (e.g., "https://code.corp.big.com").
@@ -559,4 +559,7 @@ pub enum GitHostingProviderKind {
     Github,
     Gitlab,
     Bitbucket,
+    Gitea,
+    Forgejo,
+    SourceHut,
 }