Version upgrades, add type aliases

[secam]

• Upgraded dependencies for knex, mikro-orm, typescript, immutable...
• Changed imports to work with new versions
• upgraded parser to 12.0.1 (removed set names hack)
• Added type aliases for setial8 and int8
• Added test for string insert into bigint columns (mikro-orm does this)
• Added alter enum support

[oguimbal]

Hi, I think this PR will have a lot of conflicts with #351 ... @knixeur @secam how would you like to proceed ?
Can your merge both PRs in a single PR ? Or should I merge one of those and you'll handle conflicts in the other ? In that case, which one do you prefer I merge first ?

[secam]

I think all the stuff from #351 should be skipped if we merge this. Beause #351 also upgrades mikro-orm but reimplementing workaround, that is completely removed in this PR

[knixeur]

Sure go ahead, I'll close mine 👍

[oguimbal]

released as pg-mem@2.8.1 thanks for this nice PR @secam !