Is there in vscode a shortcut available which selects all code between matching brackets e.g. in atom this shotcut is ctrl+alt+m
I suggest to remap those keys to another key, this key combination is popular, sometimes it doesn't work because of the conflict with other apps.
Open the key binding setting, type the smartselect
to find this setting, grow is expand the selection from the cursor current position to the nearest bracket, press multiple times if you want to expand or shrink to the next bracket.