Add helpers to issue certificates

[jsoriano]

Initially implemented as part of #789, moved to a separate PR for clarity.

Add package with helpers to create CAs, intermediate CAs and issue certificates with
custom names. Include helpers to load certificates and CAs from files.

Required for #654.

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• Start Time: 2022-06-15T08:55:40.988+0000

• Duration: 33 min 12 sec

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Passed	731
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Total	731

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🌐 Coverage report

Name	Metrics % (covered/total)	Diff
Packages	100.0% (31/31)	💚
Files	64.545% (71/110)	👍 0.325
Classes	59.355% (92/155)	👍 0.802
Methods	47.588% (296/622)	👍 1.065
Lines	32.013% (2667/8331)	👍 0.588
Conditionals	100.0% (0/0)	💚