Update parser to allow escape faker.js curly brace expansion #117

[matomesc]

Process % escape sequence to escape curly braces to prevent faker interpolation.

For example:

// Faker interpolation
{{name.firstName}} === 'John'

// Escape curly braces, no faker interpolation
%{%{name.firstName%}%} === '{{name.firstName}}'

// Escape %
%%{{name.firstName}}%% === '%John%'

[matomesc]

Use processors see https://github.com/RobinCK/typeorm-fixtures/issues/117#issuecomment-604546475