Add conditions ESRAP-ERROR, [SIMPLE-]ESRAP-PARSE-ERROR, LEFT-RECURSION

[scymtym]

• This patch adds condition classes ESRAP-ERROR is the superclass for esrap conditions ESRAP-PARSE-ERROR is the superclass for parse errors SIMPLE-ESRAP-PARSE-ERROR is a SIMPLE-ERROR and ESRAP-PARSE-ERROR LEFT-RECURSION is a ESRAP-PARSE-ERROR that is signaled when left recursion is detected
• PARSE signals these errors failed parse -> SIMPLE-ESRAP-PARSE-ERROR rule not active -> SIMPLE-ESRAP-PARSE-ERROR incomplete parse -> SIMPLE-ESRAP-PARSE-ERROR left recursion -> LEFT-RECURSION
• Position indication in condition reports is also slightly better:

> Could not parse subexpression #1=(OR (& #\,) (! CHARACTER)) when parsing
>
>   Expression INTEGER
>     Subexpression (AND #2=(? WHITESPACE) DIGITS #3=(AND #2# #1#))
>     Subexpression #3#
>     Subexpression #1#
>
>   Encountered at:
>         v (Line 1, Column 4, Position 3)
>     "123foo"
>    [Condition of type SIMPLE-ESRAP-PARSE-ERROR]

[nikodemus]

Many thanks! I've merged something based on this.

Main alterations (aside from missing include/ prefixes these are really just stylistic nits):

whitespace style

use plain ^ for marking the error position instead of V and >< (I find additional markers make things harder for me to read, not easier, and strongly prefer to have the actual error text both pristine and before any markers.)

esrap-parse-error -> esrap-error

use print-object for error reporting instead of a format function

don't expose the simple-esrap-error

manual fixes

[scymtym]

Thanks.