feat(choose_merge_request): add per_page option for merge request fetching

Allow users to configure the number of merge requests fetched via the
`per_page` setting in `choose_merge_request`. Defaults to 100.

Author: clement-hue-trainline

lua/gitlab/annotations.lua

@@ -256,6 +256,7 @@
 
 ---@class ChooseMergeRequestSettings
 ---@field open_reviewer? boolean -- Open the reviewer window automatically after switching merge requests
+---@field per_page? integer -- Number of merge requests to fetch (default: 100, max: 100)
 
 ---@class InfoSettings
 ---@field horizontal? boolean -- Display metadata to the left of the summary rather than underneath

lua/gitlab/state.lua

@@ -203,6 +203,7 @@ M.settings = {
   },
   choose_merge_request = {
     open_reviewer = true,
+    per_page = 100,
   },
   info = {
     enabled = true,
@@ -559,7 +560,11 @@ M.dependencies = {
         opts["not[label]"] = opts.notlabel
         opts.notlabel = nil
       end
-      return opts or vim.json.decode("{}")
+      local body = opts or {}
+      if body.per_page == nil then
+        body.per_page = M.settings.choose_merge_request.per_page
+      end
+      return body
     end,
   },
   merge_requests_by_username = {