Fix message completion trigger to work anywhere in the message (#3696)

* Fix message completion trigger to work anywhere in the message

* Add tests for display suggestion in difference message positions

* Fix suggestion trigger could support multiple mention symbol

* Remove optional parameter type and tweak argument name to hide

* Optimize the suggestions trigger using regex

* Fix the cursor at wrong position after selected suggestion

* Modify the rawSuggestionText pass data in right way

* Modify mention symbol to use regex type

* Update ElementX/Sources/Screens/RoomScreen/ComposerToolbar/CompletionSuggestionService.swift

Co-authored-by: Doug <6060466+pixlwave@users.noreply.github.com>

* Update generated mock

---------

Co-authored-by: Doug <6060466+pixlwave@users.noreply.github.com>

ElementX/Sources/Screens/RoomScreen/ComposerToolbar/View/MessageComposer.swift

@@ -15,6 +15,7 @@ typealias PasteHandler = (NSItemProvider) -> Void
 struct MessageComposer: View {
     @Binding var plainComposerText: NSAttributedString
     @Binding var presendCallback: (() -> Void)?
+    @Binding var selectedRange: NSRange
     let composerView: WysiwygComposerView
     let mode: ComposerMode
     let composerFormattingEnabled: Bool
@@ -66,6 +67,7 @@ struct MessageComposer: View {
             MessageComposerTextField(placeholder: L10n.richTextEditorComposerPlaceholder,
                                      text: $plainComposerText,
                                      presendCallback: $presendCallback,
+                                     selectedRange: $selectedRange,
                                      maxHeight: ComposerConstant.maxHeight,
                                      keyHandler: { handleKeyPress($0) },
                                      pasteHandler: pasteAction)
@@ -285,6 +287,7 @@ struct MessageComposer_Previews: PreviewProvider, TestablePreview {
         
         return MessageComposer(plainComposerText: .constant(content),
                                presendCallback: .constant(nil),
+                               selectedRange: .constant(NSRange(location: 0, length: 0)),
                                composerView: composerView,
                                mode: mode,
                                composerFormattingEnabled: false,