Add a login/login-name/username disambiguation to affected endpoint parameters and response/request models (#34901)

Issue: [link](https://github.com/go-gitea/gitea/issues/9637)

Changes introduced: I have clarified the problematic terms (`login`,
`login_name`, and `username`) in all affected endpoints.

The changes were made to relevant:
- HTTP endpoint parameters' descriptions 
- response/request models' fields

routers/api/v1/org/block.go

@@ -47,7 +47,7 @@ func CheckUserBlock(ctx *context.APIContext) {
 	//   required: true
 	// - name: username
 	//   in: path
-	//   description: user to check
+	//   description: username of the user to check
 	//   type: string
 	//   required: true
 	// responses:
@@ -71,7 +71,7 @@ func BlockUser(ctx *context.APIContext) {
 	//   required: true
 	// - name: username
 	//   in: path
-	//   description: user to block
+	//   description: username of the user to block
 	//   type: string
 	//   required: true
 	// - name: note
@@ -101,7 +101,7 @@ func UnblockUser(ctx *context.APIContext) {
 	//   required: true
 	// - name: username
 	//   in: path
-	//   description: user to unblock
+	//   description: username of the user to unblock
 	//   type: string
 	//   required: true
 	// responses:

routers/api/v1/org/member.go

@@ -133,7 +133,7 @@ func IsMember(ctx *context.APIContext) {
 	//   required: true
 	// - name: username
 	//   in: path
-	//   description: username of the user
+	//   description: username of the user to check for an organization membership
 	//   type: string
 	//   required: true
 	// responses:
@@ -186,7 +186,7 @@ func IsPublicMember(ctx *context.APIContext) {
 	//   required: true
 	// - name: username
 	//   in: path
-	//   description: username of the user
+	//   description: username of the user to check for a public organization membership
 	//   type: string
 	//   required: true
 	// responses:
@@ -240,7 +240,7 @@ func PublicizeMember(ctx *context.APIContext) {
 	//   required: true
 	// - name: username
 	//   in: path
-	//   description: username of the user
+	//   description: username of the user whose membership is to be publicized
 	//   type: string
 	//   required: true
 	// responses:
@@ -282,7 +282,7 @@ func ConcealMember(ctx *context.APIContext) {
 	//   required: true
 	// - name: username
 	//   in: path
-	//   description: username of the user
+	//   description: username of the user whose membership is to be concealed
 	//   type: string
 	//   required: true
 	// responses:
@@ -324,7 +324,7 @@ func DeleteMember(ctx *context.APIContext) {
 	//   required: true
 	// - name: username
 	//   in: path
-	//   description: username of the user
+	//   description: username of the user to remove from the organization
 	//   type: string
 	//   required: true
 	// responses:

routers/api/v1/org/org.go

@@ -82,7 +82,7 @@ func ListUserOrgs(ctx *context.APIContext) {
 	// parameters:
 	// - name: username
 	//   in: path
-	//   description: username of user
+	//   description: username of the user whose organizations are to be listed
 	//   type: string
 	//   required: true
 	// - name: page
@@ -112,7 +112,7 @@ func GetUserOrgsPermissions(ctx *context.APIContext) {
 	// parameters:
 	// - name: username
 	//   in: path
-	//   description: username of user
+	//   description: username of the user whose permissions are to be obtained
 	//   type: string
 	//   required: true
 	// - name: org

routers/api/v1/org/team.go

@@ -426,7 +426,7 @@ func GetTeamMember(ctx *context.APIContext) {
 	//   required: true
 	// - name: username
 	//   in: path
-	//   description: username of the member to list
+	//   description: username of the user whose data is to be listed
 	//   type: string
 	//   required: true
 	// responses:
@@ -467,7 +467,7 @@ func AddTeamMember(ctx *context.APIContext) {
 	//   required: true
 	// - name: username
 	//   in: path
-	//   description: username of the user to add
+	//   description: username of the user to add to a team
 	//   type: string
 	//   required: true
 	// responses:
@@ -509,7 +509,7 @@ func RemoveTeamMember(ctx *context.APIContext) {
 	//   required: true
 	// - name: username
 	//   in: path
-	//   description: username of the user to remove
+	//   description: username of the user to remove from a team
 	//   type: string
 	//   required: true
 	// responses: