feat: display label names on figures

[krishna5379chaudhary-eng]

Description

This PR adds label names to bounding box and polygon figures in the LabelLab labelling interface.

Previously, the label name was associated with the selected label but was not passed to the rendered figure, so the annotation shape did not display its label. This change passes label_name to the figure and displays it using a permanent Leaflet tooltip.

Fixes #389

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

The modified files were checked with ESLint:

npx eslint src/components/labeller/Figure.js src/components/labeller/LabelingApp.js

Result: 0 errors. Existing Prettier warnings were reported.

Also ran:

git diff --check

No whitespace errors were reported.

The application was started locally, but the local environment became stuck on the authentication page, so the bounding box/polygon UI could not be reached for browser-based verification. No changes were made to the authentication system because it is unrelated to this issue.

Test Configuration:

• Node.js: local development environment
• React: 16.13.1
• react-leaflet: 2.2.0
• OS: Windows

Screenshots: Not available because the local application could not proceed past authentication.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new errors
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules