make: consistently use double quotes in error messages

Previously, some error messages used single quotes, very few used
backticks or parentheses, most already used double quotes.

While here, reword a few error messages to be clearer or more consistent
with related error messages.

make: use '"filename" line 123' for locations instead of 'filename:123'

The format 'filename:123' is commonly used for identifying a location in
a file. Text editors recognize it and allow quick navigation through it.
The previous format was specific to make and would have required custom
support in editors.

The new format was already used in stack traces, except for the first
line. Now all lines use the same format.

make: in error message about conditionals, use single quotes

Single quotes are used less often in the conditionals themselves, which
leads to fewer confusions.

make: on error, print the targets to be made

This helps to understand situations with several nested sub-makes in
varying directories.

branches: 1.12.2;
tests/make: force line-based diagnostics to be listed in the tests

This way, contradictions between the intended output and the actual
output are closer together and have a better chance of being spotted.

make: do not evaluate misplaced expressions in malformed conditions

This change only affects the behavior for parse errors. Syntactically
well-formed conditions work exactly as before.

tests/make: extend test for parse errors in conditions

make(1): add error handling for edge case in malformed conditions

make(1): demonstrate missing error handling for malformed conditions

make(1): add remarks to the tests about conditions

make(1): add test for operator precedence using truth tables

make(1): add rationale for evaluating expression after parse error

make(1): fix line numbers from test result of the previous commit

make(1): add test for evaluation of condition after parse error

make(1): add test for unquoted string literals

make(1): add dummies for fine-grained tests, one per single feature

The test names have been derived from the current manual page.

All these tests are dummies right now, and the code from the existing
tests will be moved into the new tests step by step.

This is done to prevent modmisc, escape, varmod-edge and varmisc from
growing without any bounds, and to reduce the side-effects of one test
to the others.