Centralize ThemeColor constants

[shouples]

ThemeColor string literals like "problemsWarningIcon.foreground" and "notificationsErrorIcon.foreground" are scattered across multiple files. We chould extract these into a shared enum in src/icons.ts alongside IconNames, or split this into a more explicit src/themeIcons.ts and src/themeColors.ts since some colors may be used outside of the icon context.

• "problemsErrorIcon.foreground"

  • vscode/src/icons.ts

    Line 48 in 71b27b3

    export const ERROR_ICON = new ThemeIcon("warning", new ThemeColor("problemsErrorIcon.foreground"));

  • vscode/src/models/environment.ts

    Line 404 in 71b27b3

    this.iconPath = new ThemeIcon("warning", new ThemeColor("problemsErrorIcon.foreground"));

  • vscode/src/viewProviders/resources.ts

    Line 367 in 71b27b3

    return new ThemeIcon("warning", new ThemeColor("problemsErrorIcon.foreground"));

• "problemsWarningIcon.foreground"
  • from set up consumer group related models #3263:

    vscode/src/models/consumerGroup.ts

    Line 179 in 71b27b3

    isInactive ? new vscode.ThemeColor("problemsWarningIcon.foreground") : undefined,

• "notificationsErrorIcon.foreground"

  • vscode/src/models/flinkStatement.ts

    Line 341 in 71b27b3

    export const STATUS_RED = new ThemeColor("notificationsErrorIcon.foreground");

• "notificationsWarningIcon.foreground"

  • vscode/src/models/flinkStatement.ts

    Line 342 in 71b27b3

    export const STATUS_YELLOW = new ThemeColor("notificationsWarningIcon.foreground");

• "notificationsInfoIcon.foreground"

  • vscode/src/models/flinkStatement.ts

    Line 343 in 71b27b3

    export const STATUS_BLUE = new ThemeColor("notificationsInfoIcon.foreground");

• "charts.green"

  • vscode/src/models/flinkStatement.ts

    Line 345 in 71b27b3

    export const STATUS_GREEN = new ThemeColor("charts.green");

• "charts.lines"

  • vscode/src/models/flinkStatement.ts

    Line 346 in 71b27b3

    export const STATUS_GRAY = new ThemeColor("charts.lines");