Highlight current month in budgets. (#3111)

...ages/desktop-client/src/components/budget/MonthPicker.tsx

...-client/src/components/budget/report/ReportComponents.tsx

.../components/budget/report/budgetsummary/BudgetSummary.tsx

...ent/src/components/budget/rollover/RolloverComponents.tsx

...omponents/budget/rollover/budgetsummary/BudgetSummary.tsx

packages/desktop-client/src/style/palette.ts

packages/desktop-client/src/style/themes/dark.ts

packages/desktop-client/src/style/themes/development.ts

packages/desktop-client/src/style/themes/light.ts

packages/desktop-client/src/style/themes/midnight.ts

packages/loot-core/src/shared/months.ts

upcoming-release-notes/3111.md