util: Introduce ToIntegral<T>(const std::string&) for locale independent parsing using std::from_chars(…) (C++17)

Summary:

util: Avoid locale dependent functions strtol/strtoll/strtoul/strtoull in ParseInt32/ParseInt64/ParseUInt32/ParseUInt64

fuzz: Assert equivalence between new and old Parse{Int,Uint}{8,32,64} functions

test: Add unit tests for ToIntegral<T>(const std::string&)

refactor: Remove unused ParsePrechecks from ParseIntegral

Also:

• Remove redundant {} from return statement
• Add missing failing c-string test case and "-" and "+" strings
• Add missing failing test cases for non-int32_t integral types

Remove unused ParseDouble and ParsePrechecks

This is a backport of core#20457 and core#23156

Test Plan: ninja all check-all bitcoin-fuzzers

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D17147