fix(accessibility): add a11y linting and fix errors

.eslintrc.js

package.json

src/components/Challenge/ChallengeView.tsx

...l/LastDuelModal/__snapshots__/lastDuelModal.spec.tsx.snap

src/components/Duel/LastDuelModal/lastDuelModal.scss

src/components/Duel/LastDuelModal/lastDuelModal.tsx

src/components/Ecogesture/EcogestureCard/EcogestureCard.tsx

...EcogestureCard/__snapshots__/EcogestureCard.spec.tsx.snap

.../EcogestureFormEquipment/EcogestureFormEquipment.spec.tsx

...eForm/EcogestureFormEquipment/EcogestureFormEquipment.tsx

...pment/__snapshots__/EcogestureFormEquipment.spec.tsx.snap

...Form/EcogestureFormEquipment/ecogestureFormEquipment.scss

...components/EcogestureForm/EquipmentIcon/EquipmentIcon.tsx

...m/EquipmentIcon/__snapshots__/EquipmentIcon.spec.tsx.snap

src/components/FluidChart/FluidChart.tsx

...mponents/FluidChart/TimeStepSelector/TimeStepSelector.tsx

...StepSelector/__snapshots__/TimeStepSelector.spec.tsx.snap

src/components/FluidChart/fluidChart.scss

src/components/Konnector/KonnectorModal.tsx

src/components/Navbar/Navbar.tsx