Closes gh-20322

Closes gh-20321

Closes gh-20320

Closes gh-20198

Closes gh-20197

Closes gh-20196

Fixes gh-20134

Closes gh-20260

Closes gh-20259

Closes gh-20258

Closes gh-20257

Closes gh-20256

Closes gh-20255

Closes gh-20254

Closes gh-20253

Closes gh-20252

Closes gh-20251

Closes gh-20250

Closes gh-20249

Closes gh-20248

Closes gh-20247

See gh-20196

See gh-20198

See gh-20197

This commit makes sure that a fallback embedded datasource is not
created if no suitable connection pool is found and an url has been
explicitly registered.

This is consistent with EmbeddedDataSourceConfiguration as it is using
EmbeddedDatabaseBuilder behind the scenes and the latter does not
honour the configured URL anyway.

Closes gh-19192

Closes gh-20135

Closes gh-19926

* pr/20157:
  Upgrade CI to Docker 19.03.5

Closes gh-20157

See gh-20157

* pr/19202:
  Polish "Verify ssl key alias on server startup"
  Verify ssl key alias on server startup

Closes gh-19202

See gh-19202

See gh-19202

* pr/18915:
  Polish contribution
  Handle JSON keys containing a dot from CF environment as a single path segment

Closes gh-18915

Along with surrounding map keys with dot from VCAP_SERVICES with `[ ]`,
this commit also does that for non-alphanumeric and `-` characters so that
they are not stripped off later.

See gh-18915

See gh-18915