[Social auth] Add Github and LinkedIn providers

[LoicPoullain]

Issue

See #125, #581

Solution and steps

• Add Github provider.
• Test Github provider in @foal/examples.
• Add LinkedIn provider.
• Test LinkedIn provider in @foal/examples.

Checklist

• Add/update/check docs (code comments and docs/ folder).
• Add/update/check tests.
• Update/check the cli generators.

[codecov]

Codecov Report

Merging #591 into v1-4-0 will decrease coverage by 0.32%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           v1-4-0     #591      +/-   ##
==========================================
- Coverage   99.49%   99.16%   -0.33%     
==========================================
  Files          88       65      -23     
  Lines        1587     1083     -504     
  Branches      341      266      -75     
==========================================
- Hits         1579     1074     -505     
- Misses          8        9       +1

Impacted Files	Coverage Δ
packages/core/src/common/hooks/log.hook.ts	66.66% <0%> (-33.34%)	⬇️
packages/core/src/express/handle-errors.ts	75% <0%> (-25%)	⬇️
packages/core/src/express/create-app.ts	95.83% <0%> (-1.64%)	⬇️
.../src/openapi/metadata-getters/get-api-used-tags.ts	100% <0%> (ø)	⬆️
...ages/core/src/common/tokens/generate-token.util.ts	100% <0%> (ø)	⬆️
packages/core/src/openapi/utils/merge-tags.ts	100% <0%> (ø)	⬆️
packages/core/src/sessions/token-required.hook.ts	100% <0%> (ø)	⬆️
packages/core/src/common/utils/escape.ts	100% <0%> (ø)	⬆️
...ackages/core/src/sessions/remove-session-cookie.ts	100% <0%> (ø)	⬆️
packages/core/src/sessions/set-session-cookie.ts	100% <0%> (ø)	⬆️
... and 51 more

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