Enable/Disable Hex mode button: modify setting in existing location

[malsyned]

This button toggles the cortex-debug.variableUseNaturalFormat setting. Its value can come from the settings.json for the current User, Workspace, or Workspace Folder. If it is set in any of those places, modify it there. Otherwise, modify it in the User's global settings.json.

Fixes #1107

[malsyned]

I tested the basic functionality for this, and it worked great to select between workspace and user settings, and default to user settings if the option is unset everywhere.

I wasn't able to test the language-specific override functionality, because this particular setting doesn't seem to pull in language overrides -- at least from "[c]" or "[c++]". At any rate, that code doesn't interfere at all with this use case. I included it for completeness in case the helper routine getConfigSource() is ever needed for other settings. If it's adding complexity you don't think we need, I can take it out easily enough:

diff --git a/src/frontend/extension.ts b/src/frontend/extension.ts
index 6d08c7c..01c8337 100644
--- a/src/frontend/extension.ts
+++ b/src/frontend/extension.ts
@@ -336,22 +336,13 @@ export class CortexDebugExtension {
             ['workspaceFolderValue', vscode.ConfigurationTarget.WorkspaceFolde>
             ['workspaceValue', vscode.ConfigurationTarget.Workspace],
             ['globalValue', vscode.ConfigurationTarget.Global],
-            // Modify user settings if setting isn't configured yet
-            ['defaultValue', vscode.ConfigurationTarget.Global],
         ];
         const info = config.inspect(section);
         for (const mapping of configurationTargetMapping) {
             const [inspectKey, mappingTarget] = mapping;
-            const inspectLanguageKey = inspectKey.replace('Value', 'LanguageVa>
-            if (info[inspectLanguageKey] !== undefined)
-                return [mappingTarget, true];
             if (info[inspectKey] !== undefined)
                 return [mappingTarget, false];
         }
-        // Shouldn't get here unless new configuration targets get added to the
-        // VSCode API, only those sources have values for this setting, and th>
-        // setting doesn't have a default value. Still, do something rational
-        // just in case.
         return [vscode.ConfigurationTarget.Global, false];
     }

[malsyned]

Sorry for the flurry of updates. I noticed after creating the PR that my precedence order didn't match the API documentation. Should be all set to go now.

[malsyned]

Thank you! I appreciate your openness to my pull requests. I really like cortex-debug and its related projects, and I'm enjoying playing a small part in improving them.