Add a couple more, mostly text, reference tests for non-embedded symbolic fonts without included encoding information

I've started to look into how we can fix issue 7580, but quickly became worried that fixing it could easily mean that we'd trade one fixed PDF file for a multitude of broken ones.

Hence I started going through the history of the code that choose the fallback encoding, and noticed that it has been changed a number of times over the years to deal with various cases of weirdness/errors in non-embedded fonts.
To my relief it turned out that almost all the PRs, please see a possibly incomplete [list here], that changed this code actually included `eq` test-cases.

However, in one case it appears that a PR missed to add a test-case. Furthermore since the fallback encoding may also be the only source for creating a `toUnicode` map, changing the encoding could possibly regress only the text-selection despite a PDF file still rendering correctly.
Therefore, this PR adds one new `eq` test, and also a number of additional `text` tests for PDF files already present in the test-suite.

Note that it's obviously possible that there's a certain overlap between the added tests, but I'd be *a whole lot* more concerned with causing regressions.

test/pdfs/.gitignore

@@ -8,6 +8,7 @@
 !german-umlaut-r.pdf
 !xref_command_missing.pdf
 !issue1155r.pdf
+!issue2017r.pdf
 !issue2391-1.pdf
 !issue2391-2.pdf
 !issue3214.pdf

test/test_manifest.json

@@ -1321,6 +1321,14 @@
       "link": true,
       "type": "eq"
     },
+    {  "id": "issue1127-text",
+       "file": "pdfs/issue1127.pdf",
+       "md5": "4fb2be5ffefeafda4ba977de2a1bb4d8",
+       "rounds": 1,
+       "link": true,
+       "lastPage": 1,
+       "type": "text"
+    },
     {  "id": "issue4461-load",
       "file": "pdfs/issue4461.pdf",
       "md5": "9df4ecaae429adb5dc93d9342a53159d",
@@ -1475,6 +1483,22 @@
       "link": true,
       "type": "eq"
     },
+    {  "id": "issue2017-eq",
+       "file": "pdfs/issue2017r.pdf",
+       "md5": "5d2bc43b386496cfb8841ca677db7046",
+       "rounds": 1,
+       "link": false,
+       "lastPage": 1,
+       "type": "eq"
+    },
+    {  "id": "issue2017-text",
+       "file": "pdfs/issue2017r.pdf",
+       "md5": "5d2bc43b386496cfb8841ca677db7046",
+       "rounds": 1,
+       "link": false,
+       "lastPage": 1,
+       "type": "text"
+    },
     {  "id": "issue5256",
        "file": "pdfs/issue5256.pdf",
        "md5": "9383e17ced31f9afc940fb7898df8e68",
@@ -1763,6 +1787,14 @@
       "link": true,
       "type": "eq"
     },
+    {  "id": "preistabelle-text",
+       "file": "pdfs/preistabelle.pdf",
+       "md5": "d2f0b2086160d4f3d325c79a5dc1fb4d",
+       "rounds": 1,
+       "lastPage": 1,
+       "link": true,
+       "type": "text"
+    },
     {  "id": "ichiji",
       "file": "pdfs/ichiji.pdf",
       "md5": "66b645802d33513cd598886e017392b8",
@@ -1782,6 +1814,13 @@
       "rounds": 1,
       "type": "eq"
     },
+    {  "id": "bug864847-text",
+       "file": "pdfs/bug864847.pdf",
+       "md5": "2b62cbba5d40a769be8e611eb5b61bfe",
+       "rounds": 1,
+       "lastPage": 1,
+       "type": "text"
+    },
     {  "id": "issue925",
       "file": "pdfs/issue925.pdf",
       "md5": "f58fe943090aff89dcc8e771bc0db4c2",
@@ -2387,6 +2426,14 @@
       "link": true,
       "type": "eq"
     },
+    {  "id": "issue1936-text",
+       "file": "pdfs/issue1936.pdf",
+       "md5": "7302eb9b6a626308e2a933aaed9e1756",
+       "rounds": 1,
+       "lastPage": 1,
+       "link": true,
+       "type": "text"
+    },
     {  "id": "bug951051",
       "file": "pdfs/bug951051.pdf",
       "md5": "05d325a5112bd3f6022367dab7bc07b9",
@@ -2636,6 +2683,14 @@
       "type": "eq",
       "about": "True type font with encoding dict with no base encoding but with differences."
     },
+    {  "id": "issue3064-text",
+       "file": "pdfs/issue3064.pdf",
+       "md5": "0307415b7d69b13acaf8bd4285d9544b",
+       "rounds": 1,
+       "link": true,
+       "lastPage": 1,
+       "type": "text"
+    },
     {  "id": "issue5421",
        "file": "pdfs/issue5421.pdf",
        "md5": "273f6813758a2349090003c7c8a0d85e",