gh-35029: Implement basis_of_weight for rings of quasimodular forms
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### 📚 Description
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This PR implements the method `QuasiModularForms.basis_of_weight(k)`. It
returns a list of quasimodular forms which generate the space of weight
k. Some examples:
```
sage: QM = QuasiModularForms(1)
sage: QM.basis_of_weight(12)
[q - 24*q^2 + 252*q^3 - 1472*q^4 + 4830*q^5 + O(q^6),
1 + 65520/691*q + 134250480/691*q^2 + 11606736960/691*q^3 +
274945048560/691*q^4 + 3199218815520/691*q^5 + O(q^6),
1 - 288*q - 129168*q^2 - 1927296*q^3 + 65152656*q^4 + 1535768640*q^5 +
O(q^6),
1 + 432*q + 39312*q^2 - 1711296*q^3 - 14159664*q^4 + 317412000*q^5 +
O(q^6),
1 - 576*q + 21168*q^2 + 308736*q^3 - 15034608*q^4 - 39208320*q^5 +
O(q^6),
1 + 144*q - 17712*q^2 + 524736*q^3 - 2279088*q^4 - 79760160*q^5 +
O(q^6),
1 - 144*q + 8208*q^2 - 225216*q^3 + 2634192*q^4 + 1488672*q^5 + O(q^6)]
sage: QM = QuasiModularForms(Gamma1(3))
sage: QM.basis_of_weight(3)
[1 + 54*q^2 + 72*q^3 + 432*q^5 + O(q^6),
q + 3*q^2 + 9*q^3 + 13*q^4 + 24*q^5 + O(q^6)]
sage: QM.basis_of_weight(5)
[1 - 90*q^2 - 240*q^3 - 3744*q^5 + O(q^6),
q + 15*q^2 + 81*q^3 + 241*q^4 + 624*q^5 + O(q^6),
1 - 24*q - 18*q^2 - 1320*q^3 - 5784*q^4 - 10080*q^5 + O(q^6),
q - 21*q^2 - 135*q^3 - 515*q^4 - 1392*q^5 + O(q^6)]
```
CC: @videlec
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URL: https://github.com/sagemath/sage/pull/35029
Reported by: David Ayotte
Reviewer(s): David Ayotte, grhkm21
