Bump svgr/webpack to 6.x

[palminha]

Is your proposal related to a problem?

svgr/webpack 5.5.0 is using some "old" dependencies that are causing some npm audit and dependabot warnings
(see #12132)

Describe the solution you'd like

Bump svgr/webpack to latest version: 6.x

Additional context

SVGR v6 uses SVGO v2 under the hood and includes tons of improvement.
Might need some migration work: SVGR migration guide.

[palminha]

can it be solved by #12026 ?

[stianjensen]

Also getting a warning from yarn on install of a new project now:

warning react-scripts > @svgr/webpack > @svgr/plugin-svgo > svgo@1.3.2: This SVGO version is no longer supported. Upgrade to v2.x.x