Upd: UI - Improve Cert Ext: Add ToolTip + fix typo

[The-Lum]

Here is a PR in order to improve Certificate Extension:

• [x] Add ToolTip (with OID) on ExtendedKeyUsage (EKU) taken directly from Crypto/x509/res [with a naming like resCryptoX509] [To avoid to duplicate resources values... to debate]
• [x] Fix some French typos on ExtendedKeyUsage
• [x] Fix and change naming OcspStamping to OcspSigning (conform to OcspSigningExtKeyUsage)
• [x] Fix minor typos
• [x] Add ToolTip on KeyUsage (KU) (for Fr, En, De)
• [x] Add abbreviations (as: KU, EKU, SKI, AKI, SAN,...) at the end of the ExtName [already done on French res] (--> to debate to do the same things on English and German/Deutsche)
• [x] Add abbreviations (as: KU, EKU, SKI, AKI, SAN,...) at the end of the Dialog title (Fr, En)
• [x] Fix some typos (Fr, De)
• [x] Fix encoding (ISO/UTF-8) issues due to https://github.com/kaikramer/keystore-explorer/pull/409/commits/efad2912f8237bd08e461fed000bd1641263c5bb
• [x] Fix unicode on privatekey French resource file

[kaikramer]

Thank you! I think we can use UTF-8 in the resource bundles, after the support for Java 8 was dropped. That should make things easier.

Add abbreviations (as: KU, EKU, SKI, AKI, SAN,...) at the end of the ExtName [already done on French res] (--> to debate to do the same things on English and German/Deutsche)

That's a really good idea!