v1.2.0

• Updated PCRE2 to v10.45
• Added PcreRegex.Substitute methods which wrap the pcre2_substitute function, with support for callouts (on match, on substitution, and on case substitution). Substitute is similar to Replace but is implemented by PCRE2, and has distinct features.
• Added support for linux-arm64 runtime
• Added PcreRegexSettings.OptimizationDirectives (pcre2_set_optimize)