feat: Unify CRUD in dialog diff

[zhixzhan]

Description

Unified Adaptive dialog CRUD operations checklist

Visual Editor

• DELETE action via '...' flyout
• ADD action via '+' flyout
• PASTE action via '+' flyout

Form Editor

• UPDATE action
• UPDATE trigger
• UPDATE dialog

Shell - Toolbar

• COPY action selection
• CUT action selection
• MOVE action selection + ADD target trigger via modal
• DELETE action selection

Shell - ProjectTree

• ADD trigger via 'New Trigger...' modal
• ADD dialog via 'New Dialog...' modal
• DELETE trigger via '...' flyout
• DELETE dialog via '...' flyout

Resource types X Operations

• Dialog x Add | Update | Delete
• Trigger x Add | Update | Delete
• Action x Add | Update | Delete | Copy | Paste | Move

Task Item

refs #2699
refs #2699

Screenshots

[coveralls]

Coverage remained the same at 0.0% when pulling 713111b on zhixzhan:centralize-action2 into 4c69132 on microsoft:master.